Download work book 1-3

Q1 Choose the correct answer:
(1) The atom is a solid indivisible particle. This statement is postulated by ------------------a- Thomson.
b-Aristotle.
c- Boyle.
d- Dalton.
(2) ------------------- are required for cathode rays to be emitted in the discharge tubes.
a. Very low pressure of the gas and very low potential difference.
b. Very low pressure of the gas and very high potential difference.
c. Very high pressure of the gas and very high potential difference.
d. Very high pressure of the gas and very low potential difference.
(3) The subatomic particle which was discovered by researchers working with cathode ray tube is--a- proton
b- nucleus.
c- electron.
d- neutron.
(4) From the properties of cathode rays, they ----------------------------------a- are negatively charged.
b- are not affected by magnetic fields
c- have thermal effect.
d- (a) and (c) are correct.
(5) If the angle of deflection of alpha particles in (79Au) gold foil experiment is 500, therefore if we
replaced the gold foil by an (13 Al) aluminium foil , the angle of deflection of alpha particles will
a- 1/2 x 50°
c- more than 50°
b- less than 500
d- 50
(6) Based on his experiment, Rutherford suggested that in the atom --------------------------a. most of the atomic mass is concentrated in the nucleus.
b. the nucleus is positively charged.
c. the electrons rotate around the nucleus.
d. all (a), (b) and (c) are correct.
(7) --------------------are deflected towards the negative electrode in an electric field.
a. a- Beta particles
b- X-rays
b. c-Alpha particles
d- Cathode rays
(8) Electrons don't fall to the nucleus because ------a.
b.
c.
d.
The weak attraction between electrons and the nucleus
The presence of centrifugal force
Low speed of the electron
The attraction force of the nucleus is cancelled by centrifugal force
(9) According to Maxwell theory -------------- during its motion around the nucleus
a.
b.
c.
d.
The orbit of the electron increases
The electron keeps it energy
The orbit of the electron decreases gradually
The orbit of the electron remains constant
When electron is transferred from near energy level to far energy level from the nucleus it
will -------
a.
b.
c.
d.
Lose a quantum of energy
Gain a quantum of energy
Emit rays
Not lose energy
The difference in energy between two successive energy levels
(10)
(11)
(12)
a. Increases as we move away from the nucleus
b. Decreases as we move away from the nucleus
c. Equal
d. There is no correct answer
The energy required to transfer electron from the 1st energy level to the 2nd is
(less than – more than – equal) the energy required to transfer electron from the 2 nd
energy level to the 3rd
(13)
The maximum number of energy levels in the heaviest known atom is (5 – 7 – 8 – 14)
(14)
(Orbit – energy level – electron cloud – Bohr's model) is the accepted for description of
the orbital
(15)
When the electrons of an excited atom fall back to lower energy levels, there is an
emission of energy levels that produces -------------------------(Egypt 2010)
a- alpha particles
b- beta particles
c- spectral lines
d- gamma radiation
(16) The number of protons in a given atom equals the number of-------------------a- neutrons
b- positrons
c- electrons
(17)
d- electrons and neutrons.
-----------is considered the key which solved the puzzle of the atomic structure.
a- Wave mechanics orbital
b- Atomic spectra
c- Schrödinger’s wave equation
d- Dual nature of the electron
(18)
The study of the line spectra of the sunlight indicated that ------------------are the main
components of the sun.
a-oxygen and hydrogen
b- hydrogen and nitrogen.
c-hydrogen and helium
(19)
d- helium and neon.
In the ground state of an atom, electrons ---------------------------a- emit energy.
b- absorb energy.
c-do not absorb or emit energy.
d. radiate light.
(20)
The energy of an electron in the second energy level (L) is ------------the energy of
another electron in the fourth energy level (N).
a- more than b- less than — c- equal to
(21)
d- not equal to
When the excited electron returns back to its original level it ---------------a loses energy
b- gains energy.
c- loses quantum of energy. d- gains quantum of energy.
(22) The atomic spectral lines of hydrogen originate due to the transfer of the electron from
a.
its ground energy level to other higher energy levels.
b.
Its excited energy levels to its ground energy level.
c.
both (a) and (b) are correct.
d.
both (a) and (b) are incorrect.
(23) Bohr’s calculations revealed that, the difference in energy between the energy levels------a- decreases further from the nucleus.
c- equal.
b- increases further from the nucleus.
d- none is correct.
(24) Bohr’s atomic model was applied mainly on -------------------a- mono electron atom.
b- dielectron atom.
c- trielectron atom.
d- polyelectron atom.
(25) The essential modifications of the modern atomic theory on Bohr’s model is (are):
a.
the dual nature of the electron.
b.
the Heisenberg uncertainty “probability” principle.
c.
the Schrodinger’s wave equation.
d.
all the previous.
(26) The dual nature of the electron means that it is a(an)--------------------a.
material particle only.
b.
material particle has electromagnetic wave properties.
c.
material particle has matter wave properties.
d.
electromagnetic wave only.
(27) The subsidiary quantum number (I) defines
a.
the number of electrons in a given sublevel.
b.
the number of orbitals in a given sublevel.
c.
the number of sublevels in the second principal energy
level.
d.
the number of sublevels in a given principal energy level.
(28) Which pair of orbitals has the same shape?
a- 2s and 2p b- 2s and 3s.
c- 3p and 3d
(29)
d- more than one is correct.
The energy level (M) has-----------------------a.
three sublevels which are 3s, 3p and 3d.
b.
two sublevels which are 3s and 3p.
c.
four sublevels which are 4s, 4p, 4d and 4f.
d.
six orbitals.
(30)
The number of (p) sublevels in the heaviest known atom is--------a-7
b-1
c-6
d-5
(31)
The number of (s) orbitals in the heaviest known atom is -----------------a-1
b-3
c-5
d-7
(32)
The (p) sublevel consists of ------------------
(33)
(34)
a.
three parallel dumbbell shaped orbitals.
b.
three perpendicular spherical symmetrical orbitals.
c.
three perpendicular dumb-bell shaped orbitals.
d.
three parallel spherical symmetrical orbitals.
The spin quantum number defines -----------------a.
the number of electrons in a given sublevel.
b.
the type of motion of the electron around its own axis.
c.
the type of motion of the electron around the nucleus.
d.
the order of the principal energy level.
The number of orbitals of a given principal energy level (n) equals-------a- n.
b- n2
c- n
d- 2n2.
2011
(35)
(36)
(37)
The electron configuration of the vanadium atom V23
a  1s 2 2s 2 2 p 6 3s 2 3 p 6 4s 2 4 p 3
c  1s 2 2s 2 2 p 6 3s 2 3 p 6 4s 2 3d 3
b  1s 2 2s 2 2 p 6 3s 2 3 p 6 4s 2 4 p 1x 4 p 1y 4 pz1
d  1s 2 2s 2 2 p 6 3s 2 3 p 6 3d 5
The correct choice in the previous question is based on -----------------a- Heisenberg uncertainty principle.
b- Auf- bau principle.
c- Hund 's rule.
d- Markownikoff’s rule.
The electron configuration of the carbon atom ( C6) is ------------a- 2 electrons in the (K) level then 4 electrons in the (L) level.
b- is2 2s2 2p2
c- 1s 2 2s 2 2 p x1 2 p 1y
d- all the previous are correct.
(38) The sublevel --------------does not exist in any atom.
a-4d
b-3f
c-2p
d-1s
(39)
The symbol 3p4 means that -----------------------------a.
the (p) sublevel of the fourth energy level contains three
electrons.
b.
the (P) energy level contains (12) electrons.
c.
the (p) sublevel of the third energy level contains four
electrons.
d.
the third energy level contains the (4p) sublevel.
(40) The max number of electrons in the principal energy level can be determine from the relation
(n-2 / n2 / 2n2/ 2n+1)
(41)
The energy levels N saturated (8 – 18 – 32 – 64)
(42)
The 3rd energy level in the atom involves the sublevels (s – s,p – s,p,d – s, p ,d ,f)
(43)
The sublevel f is saturated with (5 – 10 – 14 – 9) electrons
(44)
The energy sublevels ---------- are ascending arranged according to their energies
a. 3p<4s<3d
b. 3p<3d<4s
c. 4p<3d<4f
d. 3p<4d<4s
(45)
the sublevel which is not found in the atom is (2s – 3p – 1p – 5d)
(46)
Energy sublevels in the principal energy level are ----------
a. Different in energy
b. Close in energy
c. Different in shapes
d. Different in energy and shape
(47)
The sublevel which contains three dumbbell perpendicular orbital is (s – p – d – f)
(48)
Number of orbitals in the principal energy level n is (2n 2/n2 /n )
(49)
Number of orbitals in 3d is (5 – 4 – 9 -7)
(50)
One of the following diagrams shows the correct distribution of electrons in oxygen
atom .
Q2 Write the name of the scientist(s) or philosopher(s) who:
1. Proposed the concept of the atom more than two thousand years ago.
2. Rejected the concept of the atom and believed that all substances are composed of water, air,
fire and dust.
3. Upon his ideas, it was believed that cheap metals as iron can be converted into precious metals
as gold.
4. Gave the first definition of the element.
5. Stated the first theory about the atomic structure.
6. Described the atom as a solid indivisible particle.
7. Described the atom as a sphere of a uniform positive electricity in which negatively charged
electrons are embedded.
8. Performed the gold foil experiment under the suggestions of Rutherford.
9. Discovered the nucleus of the atom.
10. Contradicted Rutherford’s atomic model.
11. Explained the hydrogen atom spectrum.
12. Concluded that “the determination of both the velocity and the position of an electron at the
same time is possible”.
13. Discovered the uncertainty principle.
14. Contributed in modifying Bohr’s atomic model and introducing the modern atomic theory.
15. Derived a wave equation which describes the electron wave motion in the atom.
16. Discovered the sublevels.
17. Explained the way of distributing electrons in the orbitals of a given sublevel.
Q3 Write the scientific term for each of the following statements:
1. A pure simple substance that cannot be changed to simpler forms by the traditional chemical
methods.
2. A stream of extremely small particles emitted during the discharge tube experiments and
caused a glow on the tube’s glass walls.
3. The substance which glows at the sites of collision with the alpha particles in the gold foil
experiment.
4. The theory that state the charged body loses its energy gradually when it moves in circular path
5. The atom is solid undividable particle
6. The atom is homogeneous sphere of positive charge in which the electrons are immersed
7. The atom is extremely small particle similar to solar system
8. Invisible rays causes glowing in the electric discharge tube
9. Positive charged particles cause glow when they collide with zinc sulphide
10. A negatively charged subatomic particle.
11. A positively charged particle that has the structure of a helium nucleus.
12. An electrically neutral subatomic particle.
13. A positively charged dense part of the atom where most of the atomic mass is concentrated.
14. The number of protons in the nucleus of an atom.
15. When an electrically charged particle moves in an orbit, it will lose its energy gradually by
emission of radiation.
16. Considered the key which solved the puzzle of atomic structure.
17. An optical instrument for light analysis.
18. A limited number of coloured lines which characterize one element from another.
19. A state in which the electron remains in the lowest allowed energy level.
20. A state in which the electron absorbs a given amount of energy sufficient to transfer it from its
level to a higher one.
21. The amount of energy absorbed or emitted when an electron transfers from one energy level to
another.
22. A definite number of visible lines produced from vapour of gases when they are heated
23. A characteristic phenomena for the element and distinguish it form other elements
24. A whole integral number represents the energy levels in the atom
25. The amount of energy that lost or gained when the electron transfer from an energy level to
another one
26. An atom gained a quantum of energy by heating or electric discharge
27. The electron is a material particle has wave properties
28. It is practically impossible to determine both location and speed of the electron at the same
time precisely.
29. Maximum of probability to find the electron around the nucleus of the atom
30. A region of space around the nucleus in which great probability to find the electron
31. The electron is a material particle which also has wave properties.
32. A type of waves associated to every moving body.
33. Stable circular orbit of particular radius.
34. An equation used to describe the electron wave motion in the atom.
35. An integer number used to express the energy of each level.
36. Numbers that define the energy, shapes and directions of orbitals.
37. A number that defines the order of the principal energy levels.
38. A number that defines the number of energy sublevels in each principal energy level. 2011
39. A principal energy level that consists of three energy sublevels.
40. A spherical symmetrical orbital around the nucleus.
41. An orbital that takes the form of two pears meeting head to head.
42. A sublevel that consists of five orbitals.
43. A sublevel that consists of seven orbitals.
44. A number that defines the number of orbitals in a given sublevel and their orientation in space.
45. A number that defines the type of motion of the electron around its own axis.
46. The electron normally occupies the lowest energy sub-shell available.
47. Electrons that are placed in a set of orbitals of equal energy (the orbitals of a sub shell), the
order of filling for the orbital is such that each orbital will be occupied by one electron before
any orbital receives a second electron.
48. Arrangement of the electrons around the nuclei of atoms.
Q4 Give reasons for each of the following statements
1. For about two thousand years, it was believed that cheap metals can be changed into precious
ones.
2. Electric discharge experiments through gases can not be carried out under normal conditions.
3. To produce cathode rays, the pressure inside the discharge tube must be reduced to 0.01mm
Hg
4. When we expose alpha particle and cathode rays to electric field they deviate opposite to each
other
5. Zinc sulphide is used to detect alpha particle
6. Rutherford's atomic model is similar to solar system
7. Electrons don't fall to the nucleus
8. Cathode rays are deflected towards the positive electrode in an electric field.
9. Thomson’s atom is electrically neutral.
10. In Rutherford’s experiment, the metal sheet is covered from inside with a layer of zinc sulphide
11. In Rutherford’s experiment, most of alpha particles passed through the gold foil without any
deflection.
12. In Rutherford’s experiment, a very small percentage of alpha particles did not penetrate the
gold foil and reflected back.
13. In Rutherford’s experiment, some of alpha particles penetrated the gold foil but were
deflected.
14. In Rutherford’s experiment, the nuclei of different elements deflect the alpha particles by
different angle.
15. Rutherford’s atom is electrically neutral.
16. Most of the mass of the atom is concentrated in the nucleus.
17. The electron does not fall inside the nucleus of the atom.
18. The contradiction between the classical mechanical laws and Rutherford’ concept concerning
the movement of electron around the nucleus of the atom
19. The line spectrum is used to distinguish between elements.
20. Spectrum of the hydrogen is composed of a group of spectral lines
21. The quantum of energy required to transfer an electron from one energy 1evel to another is
not equal
22. It is wrong to consider the electron as a material particle only.
23. Matter waves are different from electromagnetic waves.
24. The (M) energy level is filled with 18 electrons while the (3p) sublevel is filled with 6 electrons.
25. The rule (2n is applied only on the first four energy levels.
26. The principal quantum number (n) is related to both the energy of a certain energy level and
the maximum number of electrons which saturate this energy 1evel.
27. There is no (1 p) sublevel in the atom.
28. When two electrons occupy the same orbital, each one of them spins around its axis in an
opposite direction to the other.
29. The (6s) sublevel is filled with electrons before the (4f) sublevel.
1
1
1
30. The electron configuration of the nitrogen atom ( is 1s2, 2s2 2 p x , 2 p y , 2 p z but not 1S2 2S2
2 p x2 , 2 p 1y
31. In the oxygen atom (8O), the fourth electron occupies the (2p) sublevel paired with another
electron in the same sublevel instead of occupying the sublevel (3S) sublevel. 2010 Egypt
Q5 Correct the underlined words in each of the following statements:
1. Cathode rays transfer in curved lines.
2. Thomson showed that the atom is divisible particle when the proton was discovered.
3. Cathode rays are electrically neutral but α-particles are negatively charged.
4. The structure of a-particles is similar to that of hydrogen atom
5. The scientist Bohr determined that almost all of an atom’s mass is located in its nucleus.
6. Bohr used the magnetic quantum number (m) in explaining the spectrum of hydrogen atom.
7. Modern atomic theory was based on some essential modification on Schrödinger's model.
8. As a maximum, the fourth energy level can hold 6 more electrons than the third energy level.
9. Energy sublevels are designated 1. 2. 3 and 4
10. The type of orbital that has only two lobes is S orbital.
11. In the notation 2s, the number 2 represents the number of (s) electrons
12. (d) orbitals are aligned along the x, y and z axes.
13. In the same energy level, the energy of the sublevel (p) is more than that of the sublevel (d)
14. All energy levels contain (f) sublevel.
15. The sublevel 4d is filled with electrons just before 6s sublevel.
16. The total number of electrons in (s) orbitals in germanium atom (Ge32) is 15.
17. (2 , 6) is the distribution of electrons in oxygen atom according to Hund’s rule.
What is meant by:
1. Element.
9. Excited state.
2. Cathode rays.
10. Matter wave.
3. The nucleus of an atom.
11. Wave mechanics orbital.
4. A spectroscope.
12. Quantum number.
5. Electron.
13. Principal quantum number.
6. Line spectrum.
14. Subsidiary quantum number.
7. Quantum.
15. Magnetic quantum number.
8. Ground state.
16. Spin quantum number.
17. Hund’s rule.
18- Auf bau principle
Q6 Write scientific contribution of:
(1) Greek philosophers.
6. Geiger and Marsden.
(2) Aristotle.
7. Rutherford.
(3) Boyle.
8. Maxwell.
(4) Dalton
9. Bohr
(5) Thomson
10. Heisenberg
Q7 What evidence led to the conclusion that.
1. Electron is a fundamental constituent of any matter.
2. The atom is divisible but not indivisible as Dalton said.
3. Most of the atomic volume is an empty space
4. The presence of a tiny dense part (nucleus) in the atom.
5. The nucleus is positively charged
6. The line spectrum is a characteristic feature for each element.
7. The main components of the sun are hydrogen and helium.
8. Matter wave is different from electromagnetic wave.
9. Energy levels are divided into energy sublevels.
Q8 Arrange the following groups of sublevels ascending according to energy
a-2s,3p,1s,4f,5d
b-3d,5s,4p,3s,4s,2p
c- 4s, 2p ,5f, 5p ,4d
d- 5s 7s, Sd 4d, 4f, 5p
Q9 Choose from column (B) which is suitable for column(A)
A
B
1. n
a- defines the number of sublevels in a given principal energy level
2. n2
b- defines the number of orbitals in a given principal energy level.
3. 2n2
c- defines the spin motion of the electron on its own axis.
4. Ms
d- defines the number of electrons in a given principal energy level.
5. l
e- defines the order of a principal energy level.
1 - defines the number of orbitals in a given sublevel and orientation in space.
g- defines the electromagnetic wave motion of the electron in a given principal
energy level.
(2)
A
B
1 Dalton.
a- negative electrons rotate around the nucleus as in the solar system.
2.-Bohr.
b- his equation described the electron wave motion in the atom.
3- Maxwell.
c- when an electrically charged particle moves in an orbit, it will lose its energy
gradually resulting in a gradual decrease in the orbit radius.
4- Rutherford
d- the atom is a very minute solid indivisible particle.
5- Sommerfield
e- reconciled between Rutherford and Maxwell.
6-Schrodinger.
f- the single spectral line consists of fine spectral lines representing the
electrons transition between very near energy levels (sublevels).
.
g- the dual nature of the electron
(Ill)
A
b
1. The electron cloud.
a- occupies very small part of the atomic
volume.
2. The uncertainty principle.
b- the accepted model to describe the orbital.
3. The dual nature of the electron
c- It is practically impossible to determine both
the velocity and position of an electron at the
same time
4. The spin paired state.
d- the electron is a material particle and also has
wave properties.
5. The nucleus.
e- postulated by Maxwell.
f- two electrons in one orbital spin in opposite
direction.
Q10 Compare between:
1. The behaviour of an electron and an alpha particle in an electric field.
2. Matter waves and electromagnetic waves.
3. Bohr’s orbit and wave mechanics orbital.
4. 2s and 2p sublevels according to: shape and energy.
5. 4d and 4f sublevels according to: number of orbitals and saturation with electrons.
6. Principal quantum number and subsidiary quantum number.
7. Magnetic quantum number and spin quantum number
8. The second and third principal energy levels according to:
symbolic representation — number of sublevels — number of orbitals —number of electrons —
diameter — energy.
Q 11 Answer the following questions:
1. Look at the figure which shows

the angles of deflection of alpha
particles when passing near the
B

nuclei of atoms A & B. Which has
a greater atomic number the atom
45
20
A
(A) or the atom (B) and why?
2. How do the orbitals of the 2p sublevel differ from each other?
3. How do the 2p and 3p orbitals differ from each other?
4. Which of the following electron sublevel and electron orbital designations is (are) not allowed?
a- 4s sublevel.
b – 2f orbitals
c- 2d sublevel
d- 3p sublevel.
e- 4f orbitals
f- 1p sublevel
5. In which member of each of the following pairs of sublevels would an electron have the higher
energy?
a- 2sor3s
b- 3p or 3d
d- 4s or 3d
e- 3d or 4d
g- 6s or 3d
h- 5d or 6p
c- 5p or 7s
f – 4f or 5s
6. Compare between the number of s ,p ,d & f sublevels in the heaviest known atom in its ground state
?
7. What is the maximum number of electrons that can go into each of the following. Give reasons.
a- 3s
b- 2px
d- 4f
e- 5f
c- energy level M
8. Complete the figure using the following terms:
High voltage — anode — cathode — cathode rays — gas under low pressure —vacuum pump.
Then answer the following:
1. What is the value of the potential difference used to generate the cathode rays?
2. What is the value of the pressure of the gas required to generate the cathode rays?
3. What is the function of (2)?
4. What is the subatomic particle which was discovered as a result of these experiments?
9. Which is occupied by a greater number of electrons and why?
a- 3d sublevel or the second energy level.
b- Energy level with n = 1 or 2p sublevel.
c- 3p orbital or 3p sublevel.
d- 4f sublevel or the third energy level.
e- The first energy level or the third energy level.
10. What is the behaviour of cathode rays when passed through an electric field as shown in the
figure? Explain your answer.
11. How many unpaired electrons are present in each of the following in the ground state:
Al13 , C6 , O8, O+ , O-, Fe26 , Mn25 , f9 , Ar18
12. Indicate the number of:
a.
5p paired electrons in a xenon atom (54Xe).
b.
Orbitals occupied by electrons in an oxygen atom (8O).
c.
Sublevels occupied by electrons in an iron atom (26Fe)
d.
Energy levels occupied by electrons in a bromine atom (35Br)
13. An atom of an element has two electrons in the first energy level, eight electrons in the second
energy level and five electrons in the third energy level. Write the electron configuration of this atom
according to:
a- Auf-bau principle.
b- Hund’s rule.
14. Write the electronic configuration of the atoms and ions
P , S2-
, K + ,Ca and Br-1
(The atomic no. of P, S, K, Ca, & Br are 15, 16, 19,20 and 35 respectively)
15. What is wrong in each of the following electronic configurations? Explain.
(a) 1s2,2s3
(d) 1s2,2s2,2p6,3s2,3d10
(b) 1s2, 2s2, 2p2, 3s3
(e) 1s2,1p6
(c) 1s2,2s2, 3s2
(f) 1s2,2s2,2px2,2py2
16. Indicate the number of:
a.
3p electrons in a 16S atom.
b.
4s electrons in a 37Rb atom.
c.
4d electrons in a 30 Zn atom.
d.
3s electrons in a 12Mg atom.
e.
4p electrons in a 15P atom.
17. How many electrons are in the second energy level of an atom of each element of the following:
a- 14Si
b- 19K
c- 22Ti
18. How many electrons would be in an atom whose fifth energy level was completely filled?
19. Look at the following electronic configuration for a certain 12Mg atom
Energy level’
K
L
Electronic configuration:
2
8
M
N
1
1
Is this atom in the ground state? Why or why not?
20. complete the figures using the following terms:
sublevels — single spectral lines — fine spectral lines — principal energy levels
(2)
(1)
(4)
(3)
fig 2
fig 1
then answer the following questions.
a- Which figure represents the electron transition between
i- principal energy levels?
ii- energy sublevels?
b- What is the instrument used in light analysis? Who discovered the sublevels?
c- Which is more: the energy difference between the sublevels of the same energy level or that
between the different energy level?
21- What are the most important modifications on Bohr’s model upon which the modern atomic
theory is based?
22. What are the assumptions of Dalton’s atomic model?
23. What are the advantages (adequacies) of Bohr’s atomic model?
24. What are the disadvantages (inadequacies) of Bohr’s atomic model?
25- Look at the figure then answer the following questions:
Fig. (1)
Fig. (2)
a. Which figure represents the orbit concept in Bohr’s theory and which figure
represents the orbital concept in the wave mechanics theory?
b. Which concept is the correct one ? Why?
26. Write the electronic configuration of:
a- Ar and S-2
b- Fe26 and Ni28 Which pair is iso-electronic (similar) ?
27. Determine the lowest atomic numbers of the elements A, B, C, D, E & F whose electron
configuration contains the following:
1. Element A contains two completely filled orbitals.
2. Element B contains two completely filled levels.
3. Element C contains two completely filled (p) sublevels.
4. Element D contains three completely filled orbitals.
5. Element E contains three completely filled shells.
6. Element F contains three completely filled (s) sublevels.
28. The following figures represent the shapes of some orbitals:
1. What are the figures which represent the (s) orbitals?
2. What are the figures which represent the (p) orbitals?
3. What is/are the similarity/similarities and difference/s between the (p) orbitals of a given energy
sublevel?
4. Show by drawing the arrangement of the (s) orbitals according to the increasing energy, giving a
reason.
29. Write your objection about the following?
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
(13)
(14)
The spectral line of sodium Na11 is similar to spectral line of potassium atom K19
Atoms of the same element produce only one spectral line
The energy of electron in the level (L) is equal to its energy in the level (M)
The electron can be found in intermediate distance
Hydrogen atom is circular
When electron is transferred from the energy level (K) to the energy level (M) it will be
gained 2 quanta
Electron is a material particle has electromagnetic wave properties
The atomic number is number of protons in the orbitals of the atom
The 6th energy level is saturated with 72 electrons
The p sublevel consists of three parallel orbitals
The subsidiary quantum number is used to determine the order of principal energy levels
3d sublevel is filled with electrons before 4s sublevel
If there is two electrons only in p sublevel they prefer to be in one orbital
The two electrons in an orbital spin in the same direction
Questions of exams on chapter1
18. All the following are from the properties of the cathode rays except they --------------- May 2007
a- have a thermal effect.
c- are positively charged.
b- move in straight lines.
d- are effected by both electric and magnetic fields.
19. Atoms of all elements do not contain--------------------------- the energy sublevel
a- 4d
b- 3s
c- 2d
Aug. 2008
d- 2p
20. The number of orbitals in sublevel 5f is ----------------------------
May2009
a-3
b-5
c-7
d-14
21. When the electrons of an excited atom fall back to their original levels, there is an emission of ----------a)
Alpha particles
b) energy in form of spectral lines
c) Beta particles d) Gamma radiation
May 2010
22. The maximum number of electrons that occupy a given energy level (n) equals -------b. 2n2
a. 2n
c. (2n)2
d.n2
2011
Q2 What is meant by:
1. Auf — bau principle.
May96, May 99, Aug. 99, May 2000 & May 2009
2. Hund’s rule.
May 97, Aug. 99, May2005 & May 2006
3. The quantum.
May 98& May 2008
4. Electron cloud.
May2000
5. Uncertainty principle.
Aug. 2000 & May 2004
6. Subsidiary quantum number.
May2001
7. The dual nature of the electron.
8. Thomson’s model of the atom.
Aug. 2006 & Aug. 2007
May2007 & Aug. 2008
Q3 Write the scientific term:
(1)
Pairing of electrons does not happen in an energy sublevel unless all the single electrons occupy the
empty orbital first. May95
(2)
Numbers; that define the shape and the directions of the orbitals in the space.
(3)
The amount of energy absorbed or emitted when an electron jumps (is transferred) from one energy
level to another.
May 96, May 99 ,Aug. 2000, May2002, May 2005 & Aug. 2006
(4)
The principle which states that “no electron pairing takes place in a given sublevel until each orbital
contains one electron”. Aug. 96& May. 98
(5)
The quantum number that defines the orbitals of a given energy sublevel and their orientation in
space.
Aug. 98
(6)
Number of electrons or number of protons in an atom. Aug. 2000
(7)
The distribution of electrons so that each orbital contains one electron before pairing occurs.
May2003
(8)
Electrons occupy the orbitals in the order of increasing orbital energy, lowest energy orbitals are
filled first.
May2004 - Aug. 2005
(9)
A number which represents the number of orbitals within a certain energy sublevel.
May2009
Aug. 95
May 2006&
(10)
A pure simple substance that can not be changed to simpler forms by The traditional chemical
methods.
May2006
(11)
A number, in which “Bohr” used it in explaining the spectrum of the hydrogen atom, it is given the
symbol (n).
May2007
(12)
. Numbers define the volume of space where there is maximum probability of finding electrons and
they define the energy, shape and direction of orbitals.
Aug. 2007
(13)
A stream of invisible rays emitted in discharge tube with pressure 0.01 mm/Hg and potential
difference of about 10,000 volts.
Aug. 2008
(14)
The electron is a negatively charged particle which has wave properties
(15)
A number that indicates the number of energy sublevels in each energy level
May 2010
May 2011
Q4: Compare between:
1. Principal quantum number and subsidiary quantum number.
Aug.96
2. Subsidiary quantum number and magnetic quantum number. May2005 & May 2008 & May 2010
Q5: Give reasons for — Explain why — What is the scientific explanation for:
(1) In spite of the two electrons of the same orbital carry the same charge but they are never repelled each
other.
May. 98
(2) The sublevel (s) is saturated with two electrons, whereas the sublevel (p) is saturated with six electrons.
Aug. 98
(3) Electrons are preferred to occupy alone one orbital before pairing can take place in a given sublevel.
Aug. 98 & May. 2002
(4) The contradiction between the classical mechanical laws and Rutherford’s concept concerning the
movement of electrons around the nucleus of the atom.
Aug.2000
(5) Pairing of electrons takes place in one of the orbitals of(2p) sublevel in ( 8O ) atom however there is an
empty 3S level.
May 2010
(6) The matter wave associated with movement of electrons differs from electromagnetic waves May
2011
Chapter 2
Q1 Choose the correct answer:
(1) In the periodic table, the second period contains -----------elements.
a-2
b-8
c-18
d-32
(2) Elements of (s) block :
a. are found in groups I A and II A of the periodic table.
b. are located at the left of the periodic table.
c. their outer electrons are in (s) energy sublevels.
d. all the previous.
(3) The long form periodic table consists of (a.7 b. 8
c. 18 d. 10) horizontal periods
(4) p-Block elements:
a. occupy the middle block of the table.
b. occupy the left hand block of the table.
c. occupy the right hand block of the table.
d. are ten groups.
(5) ----------- includes the elements in which the sublevel 3d is filled successively.
a- The second transition series.
b- The first transition series.
c- The third transition series.
d- The fourth transition series.
(6) Actinides are -----------------------------------a- located in period 6.
b- located in period 7.
c- called rare earths.
d- b and c are correct.
(7) Actinide series and lanthanide series are similar in
a. gradually filled with electrons in sublevel 4f.
b. the unstability of their atomic nuclei.
c. each of the two series contains 14 elements.
d. both are located in the period 6 of the periodic table.
(8) The majority of ------------------- are radioactive.
a- actinides
b- lanthanides
c- halogens
d- alkali metals
(9) With the exception of helium the electronic structure of noble gases is ----------------a- ns2 np6
b- ns2
C- ns2 np2
d- ns2 np8
(10)
The representative elements include-----------------------a. the elements of p and d-blocks.
b. the elements of s and p-blocks (except noble gases).
c. the elements of the eight groups of s and p-blocks.
d. the elements of the d-block.
(11) The element whose electronic configuration is [Ar] 4s2 3d3 is a(an) -------------a- transition element.
b- inner transition element.
c- representative element.
d- noble gas.
(12) The f-sublevels of the --------------------elements are successively filled.
a- inner transition
b- main transition
c- representative
d- a and b are correct
(13) It can be predicted that element 118 would have properties similar to a(an)
a- alkali earth metal.
b- halogen.
c- metalloid.
d- noble gas.
(14) Which electron configurations represent the first two elements in group VII A of the periodic
table?
a-
1s2 2s2 and 1s22s22p63s2
c- s22s2and s22s22p1
b- 1s2,2s2 ,2p5and Ne 3s2,3p5
d - s22s22p6and Ne 3s2p6
(15) The element whose electronic configuration is [He2] 2s2 2p2 is located in --------------of the
periodic table.
a- period 4 and group IIA
b- period 2 and group IIA
c- period 2 and group IVA
d- period 4 and group IVA
(16)
What is the group, period, and block of an atom with the electron configuration
2
[ Ar]4s 3d10 4p4
a- group 4A, period 4, d-block.
b- group 6A, period 3, p-block.
c- group 4A, period 4, p-block.
d- group 6A, period 4, p-block.
(17)
An atom of an element in period 2, group (IVA) is in the ground state. What total
number of valence electrons does the atom have?
a-1
b-2
c-3
d-4
(18)
P block elements are (a.2 b. 6
c.10
d. 18)groups
(19) Elements of d block are called (representative – main transition – noble – inner transition)
(20)
La57 is (main transition – inner transition lanthanide – actinide – representative)
(21)
Element its outer most electronic configuration is 4f 15d1,6s2 is (representative – main
transition – lanthanide – actinide)
(22)
Period six in the periodic table contains (a. six
elements
b. three
c. four
d. five ) types of
(23)
The elements are arranged in the periodic table according to their
a- descending atomic numbers.
b- ascending atomic numbers.
c- descending atomic masses.
d- ascending atomic masses.
(24)
In the periodic table, all the elements within group VI A have the same number of
a- valence electrons.
c- protons.
(25)
b- energy levels.
d- neutrons.
The wave mechanics theory reveals that--------------------a.
it is possible to determine the precise location of an electron around the
nucleus.
b. it is correct to define the atomic radius as the distance from the nucleus to the
farthest electron.
c.
it is impossible to determine the precise location of an electron around the
nucleus.
d. (a) and (b) are correct.
(26)
The atomic radius is defined as------------------a. half the distance between the centers of two different atoms in a
diatomic molecule.
b. distance between the nucleus and the furthest electron in the
c. distance between the nucleus and the nearest electron in the
d. half the distance between the centers of two similar atoms molecule.
(27)
The bond length in the chlorine molecule Cl-Cl is 1.98 A°, so the atomic radius of chlorine
atom is ---------------------a-3.96A°
(28)
b- 1.98A°
d- 3.69 A°
The atomic radii increase as we go from -----------------------across a period in the periodic
table
a- up to down
(29)
c - 0.99 A°
b - right to left
c- down to up
d- left to right
The atomic radii increase with the increase in atomic number in the same group in the
periodic table due to ---------------------a) the addition of extra shells.
b) the screening effect of the inner atomic orbitals.
c) the increased repulsive forces between electrons.
d) all the previous.
(30)
Which of the following is not a reason why atomic radii increase as you move down a
group?
a- Screening effect of inner electrons.
b- Valence electrons in larger orbitals.
c- Increased charge in the nucleus.
d- Repulsion between electrons.
(31)
Which element will form an ion whose ionic radius is larger than its atomic radius?
a.
Na
b-Cl
c-Ca
d-Mg
(32)
The atom of largest size in a given period is atom of group ------------(a. 1A
b. 1B c. halogen
d. 8)
(33)
Element of largest radius in the 3rd period is (a. Na
b. Al
c. P d. Cl)
(34)
When a metallic atom combines with non-metallic atom to form a molecule, the bond
length is equal to ----------a. Sum of radii of the two atom
b. Twice radius of the metallic atom
c. Sum of radii of the two ions
d. Twice the radius of the nonmetallic atom
(35)
Cation radius is (a. more than b. less than c. equal) radius of its atom
(36)
Anion radius is (a. more than – b. less than – c. equal) radius of its atom
(37)
Ionization energy is inversely proportion to---------------------------(a. atomic radius
b. electron affinity – c. electronegativity
d. all the previous)
(38)
X  e  
 X   energy ,this equation represents -----------------
(a. electron affinity d. ionization energy)
b.  is positive
c. a chemical process associated with emission heat
(39)
Elements of the same group are similar in (a. principal quantum number b. atomic
radius
c. electronic configuration in the outer shell
d. electronegativity)
(40)
Fluorine atom has smaller electron affinity than (chlorine – bromine – iodine – astatine)
(41)
The most electronegative element is (lithium – fluorine – hydrogen – cesium)
(42)
Halogen are characterized by (small radii – higher electronegative – high ionization
energy – all the previous)
(43)
- ------------ is the amount of energy required to convert an ion with one positive charge
to an ion with two positive charges.
a- The first ionization energy
b- Excitation energy
c- The second ionization energy
d- Kinetic energy
(44)
The element which has the highest ionization energy found in of the periodic table.
a- upper left corner
b- lower right corner
c- upper right corner
d- lower left corner
(45)
Which of the following requires the most energy?
a- second ionization of 3Li
b- fourth ionization of 7N
c- first ionization of 10 Ne
d- third ionization of 4Be
(46)
The first ionization energy of 13Al is --------------------the second one.
a- more than
b- less than
c- equal to
d- much more than
(47)
It can be predicted that silicon 14Si ( will experience a large jump in ionization energy
after its ---a- second ionization.
b- third ionization.
c- fourth ionization.
d- fifth ionization.
(48)
-
The element whose atom shows the greatest affinity for an additional electron is --------a. Li
b-F
c-Cl
d-O
(49)
------------- is the tendency of an atom to attract the electrons of the chemical bond to
itself.
a- Electron affinity
b- Electronegativity
c- Ionization energy
d- Atomic radius
(50)
The lowest electronegative element found in group ------------------in the periodic table.
b. IA
b- IIA
c-VA
d- VIIA
(51)
------------- was the first scientist who classified elements into two main groups (metals
and non metals)
c. Moseley
(52)
b- Boyle
c- Berzelius
d- Hund
Metals are characterized by -------------------a. large atomic radius and high ionization energy.
b. large atomic radius and low electron affinity.
c. small atomic radius and low ionization energy.
d. small atomic radius and high electron affinity.
(53)
Non-metals are characterized by the following properties except
d. their valence shell has more than half its capacity of electrons.
e. they do not conduct electricity.
f. they gain electrons during the chemical reactions.
g. they are known as semi conductors.
(54)
On the periodic table, metalloids are found only in -------------------
a- the d-block.
b-groups lIlA through VI
c- the f-block.
d - groups IA and IIA.
(55)
One of the following elements is a metalloid which is -----------------------
a- gallium (Ga31)
c- germanium (
(56)
b- sodium (Na11)
Ge32)
d- sulphur (S16)
The most active metallic element is found in the -----------------of the periodic table.
a- upper right corner
b- lower right corner
c- upper left corner
d- lower left corner
(57)
Which of the following groups is composed entirely of nonmetals?
a- IA
(58)
b- IIIA
c-VA
d- VIIA
Which of the following oxides dissolves in water to form an acidic solution ?
a- Na2O
(59)
b- Al2O3
c- CaO
d- SO3
Where in the periodic table do you find strong base formers?
a- left
(60)
b- right
c- middle
d- inert gases
Zinc oxide is a(n)---------------------- .
a- basic oxide.
b- weak acidic oxide.
c- strong acidic oxide.
d- amphoteric oxide.
(61)
The acidic character of oxides increases in the periods when ------------------------
a- the atomic number increases.
c- the basic character decreases.
(62)
b- the atomic number decreases.
d- a and c are correct.
The basic character increases in group I A-------------------------
a- in descending the group.
b- in ascending the group.
c- with decreasing the atomic number.
d. with decreasing the atomic mass.
(63)
Moving down a group on the periodic table, which two atomic properties follow the
same trend?
a. Atomic radius and ionization energy.
b. Ionic radius and atomic radius.
rep
Look at the figure then answer the question:
H+
attraction
n
tio
(64)
M+
c
tra
at
d. Ionic radius and electronegativily.
ul s
i on
c. Ionization energy and ionic radius.
O-
if the attraction force between H+ and 0- is more than that between M+ and 0-, the substance will
ionize as ---------------------------a- an acid
b- a base.
c- an acid or a base
d- no correct answer.
(65)
The general formula of the oxygenated acid is --------------------a- [MOn (OH)m ]
b- [MO2n (OH)m]
c- [ MOn(OH2)
d- [ MO(OH)n]
(66)
The number of oxygen atoms which are not linked to hydrogen in orthophosphoric acid
(H3PO4) is ------------------a- 2
b- 1
c- 3
d- zero
(67)
Oxidation number is -------------------a- the number of hydrogen atoms that combine with an atom of the element
b- number of unpaired electrons in the valence shell
c- the number that refers to the electric charge that the atom would have in the compound
d- the number of electrons in the valance shell
(68)
-------------(a. ClO3 (OH )
(69)
Oxidation number of hydrogen in CaH2 is (a. -1 b. -2 c. +1 d. +2)
(70)
b .Si (OH )4
c. SO2 (OH )2
d. PO (OH )3 ) is strongest acid
only one of the following doesn't represent oxidation and reduction is --------a. NaOH  HCl 
 NaCl  H 2O
b. 2FeSO 4 
 Fe 2O3  SO 2  SO3
c. Zn  CuSO 4 
 ZnSO 4  Cu 
d. 2Mg  O 2 
 2MgO
(71)
one of the following reaction represents an oxidation reduction reaction
a. CuO + H2SO4 
 CuSO4 + H2O
b. CaCO3 + 2HCl 
 CaCl2 + H2O + CO2
c. Cr2O72- + 3H2S +8H+ 
 2Cr 3+ + 3S + 7H 2O
d.
(72)
NaCl + AgNO3

 Ag C l + NaCl
 Fe 2O3  SO 2  SO3 represents ----The reaction 2FeSO 4 
a. Reduction of iron
b. Oxidation of sulphur
c. Reduction of oxygen
d. Oxidation of iron and reduction of sulphur
(73) The oxidation number of iodine in KIO4 is ------------------------a- +1
b- -1
c- -7
d- +7
(74) The fluorine, oxygen and sulphur atoms in the molecules F2 , O3 and S8 respectively, have the
same
a- atomic number
b- oxidation number c- crystal structure d- chemical
properties
(75) The oxidation number of hydrogen is +1 in -----------a- HCl
b- CaH2
c- H2
d- LiH
(76) Zn + Cu+2 
 Zn+2 + Cu
The reducing agent in the above reaction is------------------------a- Zn
b- Cu
c- Zn+2
d- Cu+2
Q2.Write the scientific term for each of the following:
1. The actual energy levels in the atom.
2. A graphical representation in which the elements are arranged according to increasing atomic
number.
3. A vertical column of elements in the periodic table.
4. A horizontal row of elements in the periodic table.
5. The group of periodic table in which the outer sublevel of its elements is (ns 1)
6. A block of elements is placed on the left hand side of the periodic table and occupies two
vertical columns.
7. A block of elements whose outer most electrons occupy the p sublevel.
8. A block of elements in the periodic table that consists of 10 vertical columns.
9. Elements in which the (3d) sublevel is filled successively.
10. A series of (d) block elements located in period 5.
11. The main transition series starting with lanthanum and ending with mercury.
12. A block of elements that consists of two series each of which contains 14 elements.
13. Elements in which the (4f) sublevel is filled successively.
14. Elements in which the (5f) sublevel is filled successively.
15. Elements of the (s) and (p) blocks of the periodic table with the exception of the noble gases.
16. Elements that are found in the far right column of the periodic table.
17. Elements in which (d) sublevel is filled successively.
18. Elements of the f-block of the periodic table.
19. Half the distance between the centers of two similar atoms in a diatomic molecule.
20. The distance between the nuclei of two bonded atoms.
21. The distance between the centers of the cation and anion in an ionic crystal.
22. The amount of energy required to remove the most loosely bound electron completely from an
isolated gaseous atom.
23. The amount of energy required to convert a neutral atom (M) into monopositive ion (M+).
24. The amount of energy required to convert monopositive ion (M+1) into dipositive ion (M+2)
25. The amount of energy required to convert a dipositive ion (M +2 into a tripositive (M+3)
26. The amount of energy released when an extra electron is added to a neutral gaseous atom.
27. The tendency of an atom to attract the electrons of the chemical bond to itself.
28. Elements that are characterized by good electric conductivity and have large atomic radii.
29. A group of elements whose valence shell, generally, has more than halt its capacity of electrons.
30. A group of elements that has a metallic appearance and most of the properties of non-metals.
31. A non-metal oxide that dissolves in water forming acid.
32. A metal oxide that reacts with acids forming salt and water.
33. Metallic oxides that dissolve in water forming alkalies
34. A metal oxide that reacts with both acids and alkalies..
35. Acids that have the general formula MOn(OH)m
36. A number that refers to the electric charge (positive or negative) that the ion or atom would
have in the compound be it ionic or covalent.
37. The process of losing electrons.
38. The process of gaining electrons.
39. Reactions accompanied by a transfer of electrons from one reactant to another.
40. A type of compounds in which oxygen has an oxidation number of -1.
41. A type of compounds in which hydrogen has an oxidation number of -1.
42. The agent which gains electron(s) during the oxidation-reduction reactions.
43. The agent which loses electron(s) during the oxidation-reduction reactions.
44. A group of elements in which the outermost shell is more than half filled with electrons
45. Elements in which the valence shell has less than half its capacity with electrons
46. A group of elements in which the valence shell is nearly half filled with electrons
47. Metal oxides that dissolve in water
48. Nonmetal oxide
49. A kind of oxide reacts as acid and base
50. A property that depends on number of oxygen atoms not bonded to hydrogen in the acid
molecule
51. A number of hydrogen atoms that combine with the atom of an element
52. A number that represents number of positive or negative charge on the atom in the compound
53. A process in which the element loses electron resulting in increases of positive charge
54. A process in which the element gains electrons resulting in decrease in positive charge
55. Hydrogen compounds with active metals
56. A compounds in which oxidation number of hydrogen is (-1)
Q3. Give reasons for each of the following
1. S-Block consists of two groups of elements.
2. There are no p-block elements in the first period of the periodic table.
3. The d-block consists of 10 vertical columns.
4. The f-block contains twenty eight elements.
5. Lanthanides are known as rare earths.
6. Lanthanides are close to each other in their properties?
7. The properties of the element with atomic number 11 is similar to the element with atomic
number 19?
8. Actinides are called radioactive elements.
9. Neon (Ne10) is a noble gas.
10. Vanadium (V23) is a main transition element.
11. Elements of the same group are similar in their chemical properties.
12. Calcium 20Ca and magnesium 12Mg have nearly the same chemical properties.
13. Atomic radius cannot be physically measured by a direct method.
14. Atomic radius decreases in the periods with the increasing of the atomic number.
15. In the periodic table atomic radius increases from up to down.
16. Atomic radius of chlorine atom (Cl17) is smaller than that of sodium atom(Na10)
17. Anionic radius is bigger than atomic radius.
18. As the cationic charge increases, the radius decreases.
19. Ionization energy is inversely proportional to atomic radius.
20. The second ionization energy of an element is more than its first ionization energy.
21. The second ionization energy of sodium is very high.
22. The energy needed to remove the second electron from a lithium atom is more than that
needed to remove the fourth electron from a carbon atom. (C6)
23. Electron affinity increases in periods and decreases in groups by increasing the atomic number.
24. Ionization potential of Mg12 is smaller than ionization potential of Cl17
25. The 1st ionization energy of noble gases is so great
26. The 2nd ionization energy of sodium is more than 2nd ionization energy of magnesium
27. The value of electron affinity of Be4 and N7 is abnormal from their period ( less than expected
values)
28. Noble gases have minimum electron affinity.
29. The electron affinity of nitrogen (N7) is less than the electron affinity of carbon (C6) although
nitrogen is smaller in atomic size.
30. The electron affinity of fluorine is less than the electron affinity of chlorine although fluorine is
smaller in atomic size.
31. Metals are electropositive elements while nonmetals are electronegative elements.
32. Metals conduct electricity, while most nonmetals do not conduct electricity.
33. Metalloids are known as semi-conductors.
34. Caesium is the strongest metal while fluorine is the strongest nonmetal.
35. The nonmetal oxides are known as acidic oxides.
36. Metal oxides that dissolve in water are called basic oxide
37. Hydrogen gas evolves at anode during electrolysis of sodium hydride while it evolves at cathode
during electrolysis acidified water
38. Oxidation number of nitrogen is positive in oxygenated compounds while it is negative with
hydrides
39. Oxidation number of fluorine in all compounds is -1?
40. Oxidation number of hydrogen in metal hydride is -1?
41. The metal oxides which dissolve in water are known as alkaline oxides.
42. Magnesium oxide does not react with sodium hydroxide.
43. Antimony trioxide is an amphoteric oxide.
44. Caesium forms the strongest metal hydroxide in group IA.
45. HCIO4 acid is stronger than H3PO4 acid.
46. In modern chemistry, it is preferable to use the term oxidation number instead of the term
valency.
47. In the oxidation reduction reactions, oxidation and reduction are complementary processes.
48. Chlorine has negative oxidation number in its compounds with hydrogen e.g. HCI while it has
positive oxidation number in its compounds with oxygen e.g. Cl2O7.
Q4. Correct the underlined words in the following statements.
1. Noble gases exist at the middle of the periodic table.
2. The periodic table is divided into three blocks.
3. The second transition series is found in period three
4. The first transition series starts with lanthanum and ends with mercury.
5. The outer most valence shell of the elements of lanthanide series is 5f4
6. All the energy levels of the main transition elements are completely filled except for the highest
one.
7. The periodic table consists of 10 vertical columns and horizontal periods.
8. Elements of the same vertical group have the same number of energy levels
9. The distance between the nuclei of two iodine atoms in iodine molecules, is the radius of iodine
atom.
10. In representative elements, the atom with the smallest size, in a given period, is found in group
1A.
11. The radius of chlorine atom is equal to that of chloride ion in potassium chloride molecule.
12. Ionization energy causes the most loosely bound electron to be transferred from one energy
level to another in the atom
13.
X + e 
 X-+ energy
.
The energy released in this equation is the ionization energy
14. Iodine is the most electronegative element in the periodic table.
15. Metalloids are characterized by being electronegative elements.
16. Metals have nearly half filled valence shells.
17. Nonmetals are found in groups 3A, 4A, 5A, 6A and 7A.
18. Sulphur trioxide gas is a basic oxide
19. Magnesium sulphate is produced from reacting sulphuric acid with a non metallic oxide.
20. Sulphuric acid contains one uncombined oxygen atom with hydrogen.
21. The oxidation number of chromium in CrCl3 is —3 while it is +7 in chromium molecule.
Q5. Answer the following problems:
1. Calculate the bond length in nitrogen molecule (N2) given that the atomic radius of nitrogen
atom is 0.7 A°.
2. Calculate the atomic radius of chlorine atom given that the bond length of chlorine molecule is
1.98 A°.
3. If the bond length in the hydrogen molecule is 0.6 A° and the bond length in H-0 is 0.96 A°, find
the atomic radius of oxygen.
4. Calculate the atomic radius of carbon given that the bond length in fluorine molecule (F is 1.28
A° and the bond length in F-C is 1.41 A°.
5. If the bond length of the chlorine gas molecule (Cl2) is 1.98 A° and the radius of carbon atom (C)
is 0.77 A°, calculate the bond length of C-Cl in CCI4 molecule.
6. Calculate the bond length in N-H given that the bond length in hydrogen molecule is 0.6 A° and
the bond length in nitrogen molecule is 1.4 A°.
7. If the bond length of hydrogen iodide (HI) is 1.63 A° and the bond length of iodine (1 2.66 A°,
calculate the atomic radius of hydrogen and the bond length in hydrogen molecule.
8. Calculate the bond length in F-Cl given that the bond length of C-Cl bond is
1. 1.76 A°, bond length of Cl-Cl bond is 1.98 A° and that of F-C bond is 1.41 A°.
9. If the bond length of N-H bond in ammonia molecule is 1 A° and that of H-H bond in hydrogen
molecule is 0.6 A° and O-H bond length in H2O molecule is 0.96 A°, calculate the N-O bond
length in NO molecule.
From the following table . H-
H
Na+ Cl
Na
Atom/ion
Radius inA
1.54 0.3 1.57 0.95
Cl 
0.99 1.81
a. Calculate the bond length in the following?
i. Sodium chloride molecule
ii. Hydrogen chloride with reason?
b. Explain why the radius of sodium ion is smaller than its atom and why radius of chlorine
ion is more than radius of its atom?
10. Given that, radius of lithium ion Li+ is 0.68A and the bond length in table salt NaCl is 2.76A and
atomic radius of sodium ion Na+0.95A calculate the bond length in lithium chloride molecule
LiCl.
Q6 Choose from column (B) and (C) what is suitable for column (A)
A
B
C
1. Rb37
a- 4f10 5d1 6S2
I- locate in group zero
2. W74
b- 3d10 4S2 4p2
II- from actinides
3. Ge32
c- 4f14 5d5 6s1
III- locate in period 5 and group IA
4. Rn86
d- 5s1
IV- has the same group of Mg12
5. Ho67
e- 4f14 5d10 6s2 6p6
V- from inner transition elements
6. U92
f – 5S2
VI- from metalloids
7. Sr38
g- 6d1 5f37s2
VII- from the third transition series
b. Choose from column (B) what is suitable for column (A)
A
b
1- Actinides
a.
2- p-Block elements
are called inner transition elements and are
divided into two series
b. all their energy levels are completely filled except
for the highest level
3- Noble gases
1. 4-s-Block
2. 5-Main transition elements
3. 6-Lanthanides
4. 7-f-Block elements successively
5. 8-Representative elements
c.
have the electronic structure np6except helium
d.
are the elements whose (d) sublevel is filled
e.
occupy the right hand block of the tab
f.
consists of two groups
g.
are called radioactive elements due to the
unstability of their nuclei
h. are known as rare earths.
c. Match each numbered item on the right with the lettered item that is related to on the left:
a- group A elements.
1. periods.
b- columns.
2. representative elements.
c- group B elements.
3. groups.
d- rows.
4. transition elements.
d. Choose from column (B) what is suitable for column (A.)
A
B
1.
Atomic radius
(a) outer most electrons of the atom which are involved in bonding.
2.
Electron affinity
(b) an arrangement of elements in order of increasing atomic number.
3.
Periodic table
(c) has not a unit “unitless”
4.
Ionization energy
(d) has a lower value in group II A and VA than expected.
5.
The first ionization
energy
(e) energy required to convert an atom into an ion with one positive
charge.
6.
Bond length
(f) increases as we move from left to right in the same period.
7.
Electronegativity
(g) increases as we move downwards in the same group.
(h) it is the distance between the nuclei of two bonded atoms.
e. Choose from column (B) what is suitable for column (A)
A
B
1. Metalliods
2. Acidic oxides
a- their strength depends on the number of oxygen atoms I which are
not combined with hydrogen.
3. Amphoteric oxides
b- their valence shell has less than half its capacity of electrons
4. Non-metals
c- react with acids to give salt and water
5. Basic oxides
d- elements with properties that intermediate between metals and
nonmetals.
6. Oxygenated acids
e- they are nonmetallic oxides.
g- conduct electricity due to their large atomic size.
f - react with acids and bases.
1: their valence shell has more than half its capacity of electrons.
Q7. Match each numbered item(s) on the right with the lettered item that is related to on the
left;
a- Dissolution of a metal
1. Al2O3 + 6HCI

 2AlCl3 +3H2O
oxide in water.
b- Passing an acidic oxide
 2NaOH
2. Na2O + H2O 
through an alkali.
c- Two reactions represent
3. MgO + H2SO4 

MgSO4 +H2O
the combination of an
amphoteric oxide with an
acid and with a base.
d- The reaction between a
 2NaAIO2 + H2O
4. Al2O3 + 2NaOH 
basic oxide and an acid.
e- Dissolution of an acidic
 Na2CO3 + H2O
5. CO2 + 2NaOH 
oxide in water.
 H2SO4
6. SO3 + H2O 
Q 8. What is meant by:
1. The period.
16. Second ionization energy.
2. The group.
17. Electron affinity.
3. Representative elements.
18. Electronegativity.
4. Noble elements.
19. Metals.
5. Main transition elements.
20. Nonmetals.
6. First transition series.
21. Metalloids.
7. Second transition series.
22. Basic oxides.
8. Third transition series.
23. Alkaline oxides.
9. Inner transition elements.
24. Acidic oxides.
10. lanthanide series.
25. Amphoteric oxides.
11. Actinides.
26. Oxygenated acids.
12. Atomic radius.
27. Valency.
13. Bond length.
28. Oxidation number.
14. Ionization potential.
29. Oxidation process.
15. First ionization energy.
30. Reduction process.
Q 9 .Calculate the oxidation number of the underlined elements in the
following:
a- CaCO3
e- Na2O2
i-
FeSO4
b- K2 Sb2O7
f- O3
c- LiH
d- H2S
(g) (PO4)3-
(h) KO2
J- (S2O3)2-
(k) KO2
Q I0. dentify the oxidizing and reducing agent in the following reactions:

1. Zn + CuSO4 
2. 4P+5O2
3. Na2CO3
4.
C+O2
ZnSO4 +Cu

 2P2O5
+ MgSO4

 CO2

 Na2SO4 + MgCO3
Q 11. Explain the oxidation and reduction processes for the named
elements in the following reactions:
a- Nitrogen and manganese in:
5 KN02 + 2KMnO4 + 3H2SO4

 5KN03 + K2SO4 + 2MnSO4 + 3H2O
b- Sodium and chlorine in:
NaOH + HCI 
 NaCI + H2O
c- Iron and carbon in:
2Fe2O3 + 3CO + 3H2 
 4 Fe + 3CO2 + 3H2O
d- Chromium and sulphur in:
K2Cr2O7 + H2SO4 + 3SO2 
 K2SO4 + Cr2(SO4)3 + H2O
e- Iron and nitrogen in
Fe + 4HNO3 

Fe(NO3)3 + 2H2O + 2NO ↑
Q12. Calculate the oxidation number of:
Oxygen in
:
a- K2O
b- K2O2
c- KO2
Sulphur in
:
a- H2S
b- SO3
c- Na2SO4
Nitrogen in
:
a- N2
b- NO
c- NH2OH
d- NH3
a- CrOF4
b- CrO
c- CrCI3
d- CrF6
Chromium in
Q13. Indicate which of the following is an oxidation or reduction change?
 O2
a-O3 
 CO
b-CO2 
 FeCI3
c- FeCl2 
 MnO41d- MnO2 
Q14. Arrange the following atoms and ions ascending with reason according to—
(1)
(2)
Atomic radius
a. Ca20 , Al13, Mg12
Ionization energy
b. Ca20, Be4, N7
c. S

,Cl17 , S 16
a.
(3)
(4)
Na11 ,C 6 ,Ge 32 , Si 14
b. Br35 , Se 34 , S 16 ,O 8
c . O++ ,O8 ,O 
Electron affinity---
a. Br35 , F9 , I 53 ,Cl17
b. F9 , Li 3 , Na11 ,C 6
c . K19 , H 1 , Rb37 ,Cs 55
d. O- ,O 8 ,O 
According to electronegativity
a. Be4 , F9 , Mg 12 , N 7
b. I53, F9, Br53
Q15.Show the oxidation and reduction in the following reactions and show the
reducing agent and the oxidizing agent.
Questions on General secondary certification chapter 2
Q1: Write the alphabetical letter corresponding to the suitable choice of the correct answer for each of the
following:
1.
Oxidation number of hydrogen in CaH2 compound is --------------------a- +1
b. -1
c- —2
d. +2
2. 2. The oxidation number of hydrogen in LiH is -----------------------a- +1
3.
b. -1
c- +2
a- transition elements
b- representative elements.
c- Actinides.
d- noble gas.
4. The oxidation number of sulphur in Na2S2O3 compound is -------------------
5.
b. -4
c. +5
Ma 96
d- —2
The d-block elements are called -----------------------
a- +2
Aug. 95
May 97
May 98
d. -6
Nonmetals are characterized by their --------------------------------
May99
a- small electron affinity.
b. electro positive properties.
c- high ionization potential.
d- large atomic radii.
6. When a metal atom combines with a nonmetal atom to form a molecule, the length of the bond equals -------------------Aug. 2001
a- sum .of atomic radii of both atoms.
b- double the radius of to metallic atom.
c- sum of the radius of two ions
7. Elements in which their (d) sublevel orbitals are gradually filled with electrons are called --------Aug.2002
a- transition
8.
b. representative
d- noble.
The electron configuration of the outermost orbitals of an element is 4f7 5d1 6s2 This element is
of the ----------------- series.
May2003
a- first transition
d- third transition
The oxidation number of hydrogen in sodium hydride is ------------------a- + 1
b.
one
b- inner transition (actinides)
c- inner transition (lanthanide)
9.
c- inner transition.
-1
c- + 2
Aug. 2005
d. — 2
10. If the bond length in the chlorine molecule is 1.98 A° and the bond length between carbon and chlorine
atoms equals 1 .76A°, then the atomic radius of carbon atom is equal to ---------Aug. 2004
a-0.12A
b- 1.1 A°
c-O.77A°
d- 3.74 A°
11. In the actinides series, the sublevel is ---------------------- filled successively by electrons.
a-(3d)
b-(4d)
c-(4f)
d-(5f)
12. The oxidation number of oxygen in the hydrogen peroxide is ---------------a- (-2) b- (+2)
c- (+1)
Aug. 2006
May2007
d- (-1)
13. On the electrolysis of molten sodium hydride------------- will form at the anode. May2008
a- sodium metal
b- sodium oxide
c- hydrogen gas
d- water
14. An element its electronic configuration Xe( 6s2 5d3 4f14 )it represents --------May 2008 &May 2010
a- the second transition series.
b- the third transition series.
c- the lanthanide series.
d- the actinide series.
15. The oxidation number of chlorine in KCIO4 compound is -------------------May2009
a- (—1)
b- (+7)
c- (—7)
d- (+1)
Q2 Write the scientific term (expression) for each of the following:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
The quantity of energy required to remove the least electrons bind to a single atom in the gaseous
state.
May 95, May 97 & Aug. 97
The process of losing electrons from the element and leading to an increase in the positive charge.
Aug. 95 & Aug. 96
The amount of energy released when an extra electron is added to a neutral gaseous atom.
May 96, Aug. 98 & & Aug. 2008
The tendency of an atom to attract the electrons of the chemical bond to itself.
Aug. 99 &May
2001
Half the distance between the centers of two similar atom in a diatomic molecule. May2000 ,Aug. 2002,
May 2004 & Aug. 2007
The tendency of an atom to attract the two electrons of the chemical bond between it and another
atom to itself. May2003
The amount of energy needed to remove the most loosely bounded electron from the atom in its
gaseous state. Aug. 2003
A series of elements in which the (4f) sublevel is filled successively by electrons. Aug. 2004
A group of elements whose valence shell has less than half its capacity of electrons.
Aug. 2005
The group of elements whose valency shell generally has more than half its capacity of electrons.
May2006
A number that refers to the electric charge (positive or negative) that the atom would have in the
compound, be it ionic or covalent. Aug. 2006
The elements of the f-block, where the f-sublevels of these elements are successively filled by electrons.
May2007
Q3:Correct the underlined word:
1. The oxidation number of chlorine in NaCIO4 is -6
Aug. 95
2. In the periodic table the strong metals are placed at the top right hand side of the table where as the strong
non metals are placed at the bottom of the left hand side of the table. May97
3. Atomic radius is defined as the double distance between the centers of two similar atoms in a diatomic
molecule.
Aug. 99
4. Oxidation number of manganese in KMnO4 compound is +6
Aug. 99
5. The element with electronic configuration: is 2s2, 2p6 3s2 is present in the period two of the group three in the
periodic table. Aug. 2000
6. The oxidation number of oxygen in hydrogen peroxide is ±1/2.
May2001
7. The oxidation number of oxygen in ozone molecule is (-3) Aug. 2002
8. In the period, the values of ionization potential increase as we go to the right i.e. as the atomic radius
increases.
Aug. 2004
9. metalloids are characterized by their nearly filled valence shell with electrons, and their electronegativity is
greater than that of metals and non-metals
May 2011
10. In the lanthanide series the sublevel (5f) is filled successively with electrons and it contains (15)elements
which are all radioactive
May 2011
Q4: Write the scientific explanation: (or Give reasons for each of the following).
1. The first ionization energy of noble gases of group zero is very high. Aug. 96 & Aug. 2008
2. Atomic radii increase in the same group with the increase in the atomic number.
May97
3. The ionization potential of magnesium ( is less than the ionization potential of chlorine ( May98
4. Electron affinity of chlorine is higher than the electron affinity of fluorine inspite of the fact that fluorine
is smaller atom. Aug. 99 & May2003
5. The negative fluoride ion and the positive sodium ion have the same electronic configuration. Aug.
2001
6. The radius of nonmetal ion is larger than the radius of the corresponding atom, while the radius of the
metal ion is smaller than that of its corresponding metal atom. Aug.2002
7. Ionization potential of chlorine ( is higher than the ionization potential of sodium (
May2005
8. The values of atomic radii decrease as we go from left to right in the same horizontal periods. Aug.
2005
9. ClO3(OH) acid is stronger than PO(OH)3 acid.
May2006
10. The strongest metal is placed down the left hand block of the periodic table. Aug.2006
11. The ionization potential decreases across the elements of the same group by increasing the atomic
number.
May2007
12. The bond length in iron (II) chloride is longer than that in iron (III) chloride.
May 2008
Q5: Compare between-What is the difference between:
1. Lanthanide and actinide elements.
May95
2. Electron affinity and electronegativity.
May 98, May 2000, May 2005 & Aug. 2006
3. Metals and nonmetals (two points only).
May2007
4. Acidic oxides and basic oxides. May2008
5. The electron affinity of both chlorine and fluorine atoms.
May2009
6. The value of first and second ionization energy of magnesium (Mg (explain the reason). May2009
Q6 Calculate the oxidation number of:
1.
2.
3.
4.
5.
6.
Sulpher in H2SO4
May95 & Aug. 97
Sulpher in H2S May95
Nitrogen in NO May95 &Aug.97
Nitrogen in NH3
May95
Phosphorus in phosphorus molecule
Aug. 2003
Chlorine in ClO3-1
May2006
7.
8.
9.
10.
Sulphur in 2 3
Aug. 2007
Manganese in KMnO4 Aug. 2007
Chlorine in HCIO4
Aug. 2008
-2
Chromium in (Cr2O7) Aug.2008
S O 2
Q7Comment on the trend of:
1. The metallic and nonmetallic property in the periodic table.
May 96
Q8 What is meant by?
1. Electronegativity.
Aug. 96
3. Oxidation number.
Aug. 2000
2. Metalloids.
Aug. 99 & Aug. 2007
4. Electron affinity.
May2004&Aug. 2007
5. Representative elements.
May2008
Q 9 Write what you know about:
Amphoteric oxides.
Aug. 2000 & Aug.2005
Q 10 Problems:
1. The bond length between chlorine molecule (Cl-Cl) is 1 .98A° and the bond length between carbon and
chlorine (C-Cl) equals 1 .76A°. Calculate the atomic radius of carbon atom.
Aug. 97
2. The reaction between potassium dichromate and iron (II) chloride can take place according to the following
equation:
K2Cr2O7+ 6FeCI2 + 14HCI 
 2KCI + 2CrCl3 + 6FeCl3 + 7H2O Explain the type of change (oxidation or reduction)
that occurred to chromium and iron in the above reaction. Aug. 98, Aug. 2001 &May 2011
3. If the bond length in the nitric oxide molecule is 1 .36A° and the bond length of the oxygen molecule is 1
.32A°, calculate the ionic radius of the nitrogen atom. May 99 & May 2011
4. Calculate the bond length in fluorine molecule provided that the bond length in hydrogen fluoride molecule is
0.94A° and the bond length in hydrogen molecule is 0.6A°.
May2002
5. Show the change of oxidation or reduction (if it exists) in the following chemical reactions: May2006
electric arc
1) N 2  O 2 
 2NO
700C
 2Fe  3CO 2
2) 3CO  Fe 2O3 
6. In HCIO molecule the bond length between chlorine and oxygen atoms is 1.65A° and the bond length between
chlorine and hydrogen atoms is 1 .29 A°. The bond length in chlorine molecule is 1.98 A°. Calculate:
Aug. 2008
1) The bond length in oxygen molecule.
2) The atomic radius of hydrogen atom.
7.
Cr2O7 2  3H 2S  8H  
 2Cr 3  3S  7H 2O
May 2010
What type of change (oxidation or reduction) that occurred to chromium and sulphure in the previous reaction (
explain your answer)
Q11: Write the electronic configuration of an element with atomic number 24. Define its type, block and period
in the periodic table. May 2002
Chapter 3
Q1 Choose the correct answer for each of the following:
1. The elements A9 , B10 ,C 11 (A&C –B&B – A&B – A&C) can combine together
2. Aluminium chloride is a covalent compound because the difference in electro-negativity( more
than 1.7 – less than 1.7 – zero – equal 1.7)
3. All these elements can form chemical bonds under normal conditions except -----------------a- K
b-Kr
c-Ca
d-Cl
4. The molecule of the element 10X consists of atom (s).
a- one
b- two
c-three
d-four
5. The chemical reaction is defined as--------------------------------a- breaking bonds and forming bonds.
b- electrostatic attraction between two ions.
c- combination of the nuclei of two ions.
d- overlap of the nuclei of two atoms.
6. A chemical bond is formed between iron and sulphur when-------------------a- mixing iron and sulphur.
b- heating a mixture of iron and sulphur.
c- dissolving mixture of iron and sulphur in water.
d- none of the above.
7. The ionic bond is characterized by-----------------------------------a- it is formed as a result of transferring electrons from a metal atom to a nonmetal atom.
b- it is formed due to the electrostatic attraction force between a cation and an anion.
c- it has no materialistic existence.
d- all the previous are correct.
8. The type of bond formed between two elements of atomic numbers 35 and 11 is--------------a- pure covalent.
b- polar covalent..
c- ionic.
d- metallic.
9. Which bond is ionic?
a- H-Cl
b- S-Cl
c- Cs-F
d- a & b are correct
10. Sodium chloride is ----------------- than magnesium chloride.
a- less ionic
b- more ionic
c- less polar
d- more polar
11. The covalent bond between two ------------------atoms is formed through of a pair of electrons.
a- donating
b- accepting
c- transferring
d- sharing
12. All of the following have covalent bonds except----------------------------a- HCI
b- CCl4
c- H2O
d- KCI
13. The type of bond in aluminium chloride is-------------------------a- ionic.
b- pure covalent.
c- polar covalent.
d- metallic.
14. Which structural formula represents a non polar symmetrical molecule?
a- H2O
b- CH4
c- HF
d- NH3
15. Which substance contains a polar covalent bond?
a-H2
b-O2
c-NH3
d-N2
16. In ammonia molecule, the nitrogen atom carries ----------------partial charge(s).
a- two positive
c- two negative
b- three negative
d- one negative
17. The electronic theory of valency was proposed by------------------a- Hund and Berzelius.
b- Geiger and Marsden.
c- Kosel and Lewis.
d- Kosel and Solvay.
18. The idea of the octet rule depends on--------------------a- the tendency of the atom to reach the noble gas structure.
b- the overlapping between two atomic orbitals of two atoms each of which contains a
single electron.
cd-
the tendency of the atom to reach the octet structure.
a & c are correct.
19. We can apply the octet rule on compound.
a. NH3
b-PCl5
c-BF3
d-NO
20. The valence bond theory explains the formation of --------------------a.
ionic bond.
c- hydrogen bond.
b- covalent bond.
d- all the previous.
21. According to V.B.T. the carbon atom in methane molecule is bound to ---------------a- two hydrogen atoms through two covalent bonds.
b- four hydrogen atoms through four covalent bonds that differ in length and strength.
c- four hydrogen atoms through four covalent bonds equivalent in length and strength.
d- another carbon atom through four covalent bonds.
22. All the following statements about hybridization are right except-------------------a- it occurs between orbitals like of sublevels 2s&2p.
b- the number of hybrid orbitals equals the number of pure orbitals.
c- the shape and energy of the hybrid molecular orbitals are similar
d- it occurs between two atoms each one shares by single electron.
23. A tetrahedral molecule, XY4 would be formed if X uses a type of hybridization -----------------a- p2
b- sp2
c- sp
d- sp3
24. Which of these statements is the best expression for the sp 3 hybridization of carbon orbitals------a- the new orbitals are one (S) orbital and three( p) orbitals.
b- the (s) electron is deformed into a( p) orbital.
c- four new and equivalent orbitals are formed.
d- the(s) orbital electron loses energy to fall back into a partially filled (p) orbitals
25. All the following are true except-----------------.
a- the shape of methane molecule is tetrahedron.
b- the angle between sp orbitals in ethylene molecule is 120°.
c- acetylene molecule is a linear molecule.
d- there are five sigma bonds and one pi bond in ethylene molecule.
26. -------------- considered the molecule as one unit or a big atom with multinuclei.
a- The valence bond theory
b- The octet rule
c- The electronic theory of valency
d- The molecular orbital theory
27. The sigma bond is formed due to--------------------- .
a- the overlap of two atomic orbitals side by side.
b- the collateral overlap.
c- the overlap of two atomic orbitals head by head.
d- the overlap of two parallel atomic orbitals.
28. The sigma bond between carbon atoms in acetylene molecule is formed as a result overlap --------------- head to head
a. S&SP2 b. SP&SP
c. SP2&SP2
d. SP&SP2
29. The bond that includes an upper and lower sharing of electron orbitals is called---------------a- a sigma bond
b- a pi bond.
c- a hydrogen bond
d- an ionic bond.
30. The pi bond is formed due to--------------------a- the overlap of two atomic orbitals side by side.
b- the overlap of two atomic orbitals head by head.
c- the collateral overlap of orbitals.
d- a and c are correct.
31. In acetylene molecule--------------------------a- one sigma bond is formed due to the overlap of sp and sp orbitals.
b- one sigma bond is formed due to overlap of p, and p orbitals.
c- two sigma bonds are formed due to overlap of s and sp orbitals.
d- a and c are correct.
32. Which compound has a pi bond in its structure?
a- CH4
b- C2H4
c- C2H2
d- more than one is correct
33. In the solution of hydrochloric acid in water-----------------a- coordinate bond is formed between hydrogen ion and water molecule.
b- hydronium ion is formed where oxygen atom is a donor and positive hydrogen ion is an
acceptor.
c- chlorine is a donor atom and oxygen is an acceptor.
d- a and b are correct.
34. Which molecule can form a coordinate covalent bond-----------------------H
a-
H N
b- H H
H
c-
H C H
H
H
35. Which compound contains ionic, covalent and coordination bonds at the same time?
a- KCI
b- NH4Cl
c- MgCI2
d- CCI4
36. The bonding that is most significant in explaining the variation in the boiling point of water
from the boiling points of similarly structured molecules is---------------------------a- hydrogen bonding.
b- ionic bonding.
c- covalent bonding.
d- coordinate bonding.
37. The compound that can form hydrogen bonds are characterized by ----a. Solubility in water
b. High boiling point
c. Variable shapes
d. All the previous
38. Which one can’t form hydrogen bond (H2O – HF – CH3OH – H2S)
39. Ammonium chloride molecules contains (coordinate – covalent – ionic – all) bonds
40. The bond between hydrogen and oxygen in a water molecule is (polar covalent – hydrogen –
coordinate – pure covalent)
41. The strength of hydrogen bond depends on ---------------a. The difference in eelctronegativity
b. The degree of ionization
c. Concentration of the solution
d. Number of lone pairs of electrons
42. The bond between water molecules is (polar covalent – hydrogen – coordinate – pure covalent)
43. The coordinate bond is formed between two atoms --------a. One is donor and the other is acceptor
b. Each has vacant orbital
c. Each has lone pair of electrons
d. Each shares by an electron
44. The hydrogen bond is (longer than – shorter than – equal to ) covalent bond
45. The metallic bond is formed from the electronic cloud of ( d sublevel – positive ions – free
valence electrons – lone pair of electrons)
46. The metallic bond between aluminium atoms is (stronger than – weaker than – equal to ) the
metallic bond between sodium atoms
47. Hydrogen bond may take the shape of (linear – cyclic – net – all the previous)
48. Which kind of bonds are found in a sample of water?
a- Hydrogen bonds.
b- Covalent bonds.
c- Both ionic and hydrogen bonds.
d- Both covalent and hydrogen bonds.
49. Hydrogen bonds are strongest between the molecules of----------------------a-HF
b-HCl
c-HBr
d-Hl
50. The boiling point of water is higher than the boiling point of ammonia because----------------a- the electronegativity of oxygen is more than that of nitrogen.
b- the polarity of bonds in water molecules is higher than that of NH 3
c-
the hydrogen bonds between water molecules are stronger than the hydrogen bonds
between ammonia molecules.
d-
all the previous are correct.
51. The bond between copper atoms in copper metal is---------------------------
52.
a- pure covalent bond
b- ionic bond.
c- metallic bond
d- coordination bond.
13Al
is harder than 11Na due to---------------------------
a- the number of valence electrons in Al is more than Na.
b- aluminium has stronger metallic bond.
c- the number of associated electrons forming the electron cloud in Al is more than Na.
d- all the previous.
Q2 Write the scientific term for each of the following statements:
1. Breaking bonds between reactant molecules and formation new bonds between the products
2. The bond formed mostly between metals and nonmetals
3. The ion formed when the atom loses one electron or more
4. The bond formed between two elements , one has small ionization energy and the other has
high electron affinity
5. The bond formed between two elements have the same electro-negativity
6. The bond formed between two nonmetallic atoms by sharing unpaired electrons in the
outermost shell
7. The bond formed between two elements when the difference in electro-negativity is less than
1.7
8. The bond formed as a result over two atomic orbitals head to head
9. The bond formed as a result overlap two atomic orbitals side by side
10. With the exception of (H, Li, Be) all the elements tend to reach octet structure
11. The theory that considered the molecule is a big atom has multinuclei in which all atomic
orbitals over lap to form molecular orbitals
12. An electrostatic attraction between positive and negative ions in their crystal lattice.
13. A chemical bond in which the source of the electron pair forming it is two bonded atoms.
14. A covalent bond in which the electron density is symmetrically distributed.
15. Bonding between two atoms with an intermediate difference in electronegativity.
16. The theory which assumed that covalent bond is formed due to the overlap between two
atomic orbitals of two atoms each one contains a single electron.
17. Carbon atom contains four unequivalent single electrons.
18. Carbon atom contains four equivalent electrons.
19. Carbon atom contains two unpaired (single) electrons.
20. The process of mixing two or more of different atomic orbitals of the same atom to produce an
equal number of new identical orbitals.
21. The electronic geometry and the common hybridization resulting from mixing one s orbital and
three p orbitals from the valence shell of the central atom.
22. A bond resulting from the head-on overlap of atomic orbitals, in which the region of electron
sharing is along and symmetrical to the imaginary line connecting the bonded atoms.
23. A covalent bond between sp-sp orbitals.
24. A covalent bond between p - P orbitals.
25. A bond resulting from the side —side on overlaps of atomic orbitals, in which the regions of
electron sharing are above and below the imaginary line connecting the bonded atoms, and
parallel to this line.
26. A theory that considered the molecule as one unit or a big atom with multi
27. An orbital resulting from overlapping and mixing of atomic orbitals of different atoms that
belongs to the molecule as a whole.
28. The common hybridization resulting from mixing one s orbital and one p orbital from the
valence shell of the central atoms.
29. A covalent bond resulting from the sharing of six electrons (three pairs) between two atoms.
30. A bond in which the shared electron pair comes from the lone pair of one atom.
31. An ion formed from the combination of a water molecule with a positive hydrogen ion.
32. An intermolecular attraction forces between molecules containing hydrogen directly bonded to
a small, highly electronegative atom such as nitrogen, oxygen or fluorine.
33. A bond produced from the electron cloud of valence electrons which decreases the repulsive
forces between the positive metal ions in the crystal lattice.
Q3 Mention scientific reason for each of the following:
1. Noble gases form monatomic molecules.
2. Most elements tend to take part in a chemical reaction.
3. The bond formed between metals and nonmetals is usually ionic.
4. Sodium chloride is more ionic than magnesium chloride.
5. Aluminium chloride is a polar covalent compound but not ionic although it is formed from a
metal and nonmetal.
6. Both sodium ion and fluoride ion are iso-electronic
7. Sodium chloride conducts electricity more than magnesium chloride
8. The bond formed in oxygen molecule is pure covalent bond.
9. The difference in electronegativity between the two bonded atoms in a pure covalent bond is
zero.
10. Water is a polar molecule.
11. The electronic theory of valency is not sufficient to explain the bonding and properties of
covalent molecules.
12. Although the carbon atom has two single electrons in the ground state, it forms four equivalent
bonds in methane molecule.
13. 2s and 2p orbitals of the same atom can be mixed together forming hybrid orbitals.
14. The angle between the hybrid orbitals in ethylene molecule is 120 0.
15. Sigma bond is stronger than pi bond.
16. The angle in acetylene molecule is 180
17. The four bonds in methane are equal in length and strength
18. Acetylene is chemically more reactive than methane
19. The bonds between the two carbon atoms in ethylene molecule have different strength.
20. Acetylene is more active than methane.
21. The type of hybridization in the carbon atom affects the type of bonds that can form.
22. Coordinate bond is considered as a type of covalent bond.
23. In ammonium ion, nitrogen is called donor atom while H is called acceptor atom.
24. The polar hydrogen chloride compound changes to completely ionized compound when
dissolving in water.
25. Both water and ammonia can form coordination bonds.
26. Abnormality of the boiling point of water.
27. The hydrogen bond between hydrogen fluoride molecules is stronger than hydrogen between
water molecules
28. Hydrogen bonding makes life possible (given that the predicted boiling point of water according
to its molecular mass is -80°C while the actual boiling point of water is 100°C).
29. The ammonia molecule can form coordination and hydrogen bonds.
30. The hydrogen bond between hydrogen fluoride molecules is stronger than that between water
molecules.
31. Boiling point of water is more than that of ammonia.
32. The strength of metallic bond increases as the number of valence electrons increases.
33. Sodium (Na11) is softer than magnesium (Mg12)
Q4 Identify the type of bond(s) in each of the following:
1. Potassium chloride.
7. Ammonium hydroxide molecule.
2. Ethylene molecule.
8. Acetylene molecule.
3. Diluted hydrochloric acid.
9. Nitrogen molecule.
4. A sample of hydrogen fluoride.
10. Methane molecule
5. Hydronium ion.
11. Water molecule.
6. Aluminium chloride molecule.
Q5 Identify the type of orbitals which are involved in the formation of the following
bonds:
1. The sigma bonds formed between the carbon atom and the hydrogen atoms in the methane
molecule.
2. The sigma bond formed between the two carbon atoms in the ethylene molecule.
3. The pi bond formed between the two carbon atoms in the ethylene molecule.
4. The sigma bonds formed between the carbon and hydrogen atoms in the ethylene molecule.
5. The sigma bonds formed between the carbon and hydrogen atoms in the acetylene molecule.
6. The sigma bond formed between the two carbon atoms in the acetylene molecule.
7. The two pi bonds formed between the two carbon atoms in the acetylene molecule.
Q6 What is meant by each of the following:
1. The chemical reaction.
7. The molecular orbital theory.
2. The ionic bond.
8. The sigma bond.
3. The covalent bond.
9. The pi bond.
4. The electronic theory of valency.
10. The coordination bond.
5. The valence bond theory.
11. The hydrogen bond.
6. The hybridization.
12. The metallic bond.
Q7 Compare between:
1. Ionic and covalent bonds.
2. Pure and polar covalent bonds.
3. V.B.T and M.O.T from the following point of view.
(the atomic orbitals, used in the formation of bonds).
4. Sigma and Pi bonds.
5. Methane, ethylene and acetylene according to the following points:
i- Shape.
iii- Type of hybridization.
molecule.
ii - Angle between bonds.
iv- Type and number of bonds formed in each
6. Covalent bond and coordination bond.
7. Metallic bond and hydrogen bond.
Q8 Which is more and why?
1. 1. The polarity of C-N bond or C-O bond.
(C6 , N7, O8)
2. The ability of hybrid orbitals or pure orbitals to overlap.
3. The number of pi bonds in ethylene or acetylene.
4. The boiling point of water or that of hydrogen sulphide.
5. The strength of hydrogen bond or covalent bond.
6. The melting point of 13Al or 11Na.
7. The ionic bond character in MgCl2 or CaCI2.
(12Mg,
8. Electrical conductivity of molten NaCI or that of MgCI2
20Ca)
((12Mg,
20Ca, 17Cl)
Q9 Correct the underlined words giving reasons:
1. The most stable elements in the periodic table are the metals
2. The bond formed between two elements whose electronegativities are l .2 and 3 is pure
covalent
3. Two atoms of an element of atomic number 7 combine together by a polar covalent bond.
4. The type of bond in HCI molecule is pure covalent
5. The angle between sp orbitals in methane molecule is 90°.
6. Ammonium ion is formed due to pure covalent bond between ammonia and hydrogen atom.
Q10 Choose the type of bond from column (B) which is suitable for each one in column
(A)
A
B
1. Cl2
I- three polar covalent one coordinate and one ionic bond.
2. NH4Cl
II- four covalent bonds
3. A piece of sodium metal
Ill- one pure covalent bond.
4. C2 H2
IV- triple covalent bond.
5. H3O+
V- Three polar covalent bonds.
6. NH3
VI- metallic bond.
7. CH4
VII- three sigma and two pi bonds.
8. N2
VIII- two polar covalent bonds and one coordinate bond.
Q11 Choose the type of bond from column (B) which s suitable for each suitable in column (A).
A
B
1. The type of bond between atoms of potassium and chlorine in
a crystal lattice of potassium chloride.
I. Pure covalent bond
2. The type of bond between the atoms in a nitrogen molecule.
II. Metallic bond
3. A bond in which the shared electron pair comes from the lone
pair of one atom
III. Ionic bond
4. The type of bond between the atoms In a molecule of CO2
(electronegativaty difference = (1)
IV. Hydrogen bond
5. The type of bond between the atoms of calcium in a sample of
calcium metal.
V. Polar covalent
VI. coordinate
Q12 Choose from column (B) and (C) which is suitable for column (A).
A
B
C
1- KCI.
a- non polar covalent
substance.
I- the more electronegative atom carries –ve
charge
b- amorphous substance.
II- the metal +ve ions swim in a sea of
electrons
2 -HCI.
3-CH4.
c- ionic substance.
4- Li.
d- polar covalent substance.
e- metallic network
III- The central atom undergoes
p3hybridization
IV- conducts electricity
Q13 Answer the following:
1. Use the following choices for questions (a) through (e):
1. hydrogen bonding. 3. polar covalent.
2. ionic.
4. pure covalent.
5. metallic.
6. coordinate covalenti
a- When the electronegativity difference between two atoms is 2, what type bond can be
predicted?
b- If two atoms are bound in such a way that one member of the pair is supplying both
electrons that are shared, what is the type of bond called?
c- Which of the above bonds explain water’s abnormally high boiling point.
d- When electron pairs are shared equally between two atoms, what is the bond called?
e- If the sharing of an electron pair is unequal, what is this sharing called?
2. Which of the following is not true of an atom obeying the octet rule?
a- Obtains a full set of eight valence electrons.
b- Acquires the valence configuration of a noble gas.
c- Possesses eight electrons in total.
d- Has a s valence configuration.
3. Argon has only one more proton than chlorine. Explain why these two gases have such different
chemical properties.
4. Predict which solid in each of the following will have the higher melting point. Explain your
answer.
a- NaCI or CsCI
b- 19K or 20Ca
c- MgCl2 or AICI3
5. What is the maximum number of hybrid orbitals that a carbon atom can form? Explain your
answer.
6. Locate the sigma and pi bonds in the following molecules.
O

a-
H C  H
b- H  C  C  H
7. For each pair, indicate the more polar bond by circling the negative end of the bond.
a- C-S , C-O
b- C-F, C-N
c- P-H, P-Cl
( 1H, 6C, 7N, 8O, 9F, 15P, 16S, 17Cl)
8. For each of the bonds listed, say which atom is more positively charged.
a- C-H
b- C-N
c- C-S
d- C-O
9. The melting point of beryllium is 1278°C, while that of lithium is 180°C. Account for the large
difference in values.
( Li3- Be4)
10. Which of the following compounds would you expect to be ionic:
(S O3 -
Na2O
–
CaCl2)
( 16S, 8O, 17Cl, 20Ca)
11. Using electronegativity values, predict whether the bonds in
a-CaO
b-HI
c-Br2
d-HCl
are pure covalent, ionic or polar covalent
(Electronegativity of Ca =1.0, O = 3.5, H = 2.1 , I = 2.5,
Br = 2.8, Cl =3.0
12. Classify the following molecules into ionic and covalent molecule giving reason:
a-S8
b- H2O
c- SO2
d- LiF
e- NaBr
f- KCI
g- I2
13. From the following elements:
11Na, 8O,
19K
,
6C,
12Mg
,
a- Form a covalent compound.
17Cl
b- Form the possible ionic compounds
c- Arrange the metallic elements in an ascending order according to if melting points. Explain
your answer.
14. According to Lewis and Kosel theory, explain how the covalent bond formed in the following
molecules:
( 1H, 6C, 15P, 17Cl)
a- Phosphorous trichloride
b- Methane
c- Ethylene
15. State valence bond theory. Give an example to explain it.
16. State the theory performed by Lewis and Kosel, What are its disadvantages
17. What is the type of bond formed due to the overlap of:
a. sp orbital with (s) orbital in methane molecule.
b. sp orbital with sp orbital in ethylene molecule.
c. sp orbital with (s) orbital in acetylene molecule.
d. p orbital with p orbital in C molecule.
e. sp orbital with sp orbital in C molecule.
f. p orbital with P orbital in C molecule.
18. A, B, C and D are four elements which have atomic numbers 1, 6, 17, 19 respectively.
a- Use the following choices AC, DC , AA to answer the following:
1. An ionic compound
3. A pure covalent molecule
2. A polar covalent compound
b- Write the compound name and the hybridization type when:
1. An atom of B combines with four atoms of A.
2. Two atoms of B combine with four atoms of A.
3. Two atoms of B combine with two atoms of A.
20. Mention the aspects of hybridization?
21. Explain the structure of methane molecule according to V.B.T.
22. Elements 8X, 11Yand 13Z and Which one can be a donor atom in a coordinate bond and why?
23. Explain what happens when:
a- Dry HCI gas is passed through water.
b-Ammonia gas is passed through water.
24. Mention three compounds that can form hydrogen bonds.
25. Arrange the following metals in the order of increasing hardness (g reasons).
a. Magnisum — Sodium —Aluminum
26. What are the shapes of the molecules containing the hydrogen bon& (give examples with
drawing)
27. The following diagram shows a sodium atom and a chlorine atom:
A
B
1.
Which sphere represents a sodium atom and which sphere represent chlorine atom.
2.
If an atom of (A) combined chemically with an atom of (B), what is the type bond
formed? Draw a diagram showing the molecule AB. Make the resizes of both (A) and
(B) realistic.
28. Locate the sigma and pi bonds in the following molecule then mention the of hybridization
taking place in the carbon atoms numbers (1) and (2
29. The following figure shows the structure of ethylene molecule:
a- Which represent the hybrid orbitals ,the black or white orbitals ?Explain your answer.
b-What is the type of bonds (1) and (2)?
Q14 What is meant by:
1. Chemical reaction.
3. Covalent bond.
2. Ionic bond.
4. Coordinate bond.
5. Hydrogen bond.
Q15 Choose the correct answer:
1. Three elements of atomic numbers C11, B10 , A9 : the possible combination takes place
between the atoms ----------------------------a- B with C
b- A with B
c- B with itself
d- C with A
2. When two atoms of an element of atomic number 9 combine together to form a molecule, the
formed bond is -----------------------
a- metallic.
b- coordinate.
c- ionic.
d- covalent.
3. The bond in hydrogen fluoride molecule is polar covalent because the atoms are different in--a- location in periodic table.
b- electronegativity.
c- electron affinity.
d- ionization potential.
4. sp hybridized orbitals are characterized by------------------------a- they are three in number.
c- they are linear in shape.
b- they are two orbitals.
d- (b and c) are correct.
5. In acetylene molecule----------------------a. the two carbon atoms are linked by one sigma and one pi bonds.
b. the two carbon atoms are linked by one sigma and two pi bonds.
c. the two carbon atoms are linked by sp hybridized orbitals.
d. (b and c) are correct.
6. (sp3) hybridized orbitals produced from the overlap of --------------a- one s and two p orbitals.
c- one s and three p orbitals.
b- two s and two p orbitals.
d- one s and one p orbitals.
7. When two oxygen atoms combine together to form a molecule , this process takes place bya. each atom shares by one electron to form one covalent bond.
b. one atom donates a lone pair of electrons to the other one
c. each atom shares by two electrons.
d. a polar covalent bond is formed between the two atoms.
Q16 Give reasons:
1. However oxygen and sulphur are located in group six in the periodic table ,the boiling points of
their hydrogenated compounds have different boiling points, i.e. water boils at 100C whereas
hydrogen sulphide boils at — 61°C.
2. The negative fluoride ion and the positive sodium ion are isoelectronic.
3. A coordinate bond is formed in ammonium molecule.
Q17 Answer the following:
1. Explain the expected bond in each of the following compounds.
KCI -
NO -
SO2
HCI
-
CaO
2. Arrange the following bonds according to their polarity.
H-Cl ,
C=O
H-H,
N-O,
P-Cl
(Electronegativity of O=3.5, H = 2.1 , Cl = 3, N = 3, P = 2.1 , C = 2.5)
Q18 Write the scientific term for each of the following:
1. A bond formed by the collateral overlap of two atomic orbitals.
2. A bond formed when hydrogen atom is located between two atoms of high electronegativity.
3. Ion formed when hydrogen ion links with water molecule.
4. Bond formed between two atoms the difference in electronegativity between them is zero.
Questions of General Secondary Examinations From 1995
to 2010
Q1 Choose the alphabetical letter which represents the correct answer for each of
the following sentences:
1. Type of hybridization of carbon atom in ethylene molecule is ----------b- sp2
a- sp
c- sp3
2. The bond in hydrogen chloride molecule is-----------------------a- ionic bond.
May95
May96 , Aug 2007
b- pure covalent bond.
c- coordinate bond.
d- polar covalent bond.
3. An element has atomic number 9, the type of bond in a molecule formed from the combination
of two atoms of it, is -----------------------------Aug. 96, May97
a- metallic.
b- coordinate.
c- ionic
d- covalent.
4. Type of hybridization of carbon atom in methane molecule is ------a- sp
b- sp2
c- sp3
Aug.97
d- s2 p3
5. The bond that exists in molecule of an element has the atomic number 17, is---------- May99,
May2000
a- ionic.
b- coordinate. c- pure covalent.
d- metallic.
6. Collateral overlap of atomic orbitals gives------------ bond. Aug. 2000
a- sigma
b- pi
c- metallic
d- coordinate
7. The bonds in methane molecule are formed by the overlap of the orbitals----------------May2001
a- s with sp3
b- s with sp2
c- s with sp.
d- sp with sp.
8. The hybridized orbitals sp2 are characterized by the following, except---------a- their number is 3.
Aug. 2001
b- they form tetrahedron in the space.
b- the angle between orbitals = 120°. d- they form planar triangle
9. The angle between sp hybridized orbitals are--------------a- 100°
b- 120°
c- 109°28’
May2002
d- 180°
10. A pure covalent bond is formed when the difference in the electronegativity of the two atoms
is equal to ---------------------May2003
a-1.7.
b-more than
c- slightly less than 1.7 .
d- zero.
11. The bonds between the water molecules are--------------- bonds. May2004
a- pure covalent
b- polar covalent
c- coordinate
d- hydrogen
12. The bonds between hydrogen and oxygen in a molecule of water are---------bond Aug. 2004
a- pure covalent
b- polar covalent
c- coordinate
d- ionic
13. The ionic bond is often formed between -------------------- Aug 2006
a. Different metals
c. nonmetal and non metal
b. metals and non metals
d. metalloids
14. The bond in ammonium hydroxide molecule is ------------------ bond
a. Polar covalent
b. Coordinate
c. Ionic
May 2008
d. All the previous
15. Ammonium chloride NH4Cl contains ------------------ bonds
May 2009
Polar covalent
b. Coordinate
c. Ionic
d. All the previous
16. The strongest hydrogen bonds are those between the molecules of -------------- May 2010
a. HF
b. HCl
c. HBr
d. HI
Q2 Choose the right answer for the following statement, then explain your choice:
1. When ammonium ion is formed, ammonia molecule is linked with the proton to form
bond.May2005
a- ionic
b- coordinate
c- covalent
d- metallic
Q3 Complete the following sentences:
1. 1. Type of hybridization in acetylene molecule is -------------- while the type in case of ethylene
molecule is --------Aug. 95, Aug. 98
2. 2. The------------- bond results from the head to head overlap between atomic orbitals
May96
3. 3. The bond between the chlorine atoms in chlorine molecule is -----------bond whereas the
bond in hydrogen chloride gas is ---------------- bond.
May98
4. 4. As the number of---------------- increases in the metal atoms, the atoms become more strongly
bound and accordingly the metal becomes more hard and has a-----------------melting point
Aug. 99
5. 5. The melting points of the ionic compounds are-------------- while the melting points of the
covalent compounds are---------------Aug. 2000
6. 6. The strength of metallic bond increases as the number of valency electrons of the metal
atoms ---------May2001
7. 7. The coordinate bond is formed between two atoms, one atom is called ---------------and the
other is called--------------Aug. 2002
8. The --------------------- bond is formed as a result of the overlap of two atomic orbitals side by
side.
Aug. 2004
9. (sp)hybridized orbitals are characterized by ----------a. Three orbitals
c. Two orbitals
b. Linear in shape
d. Two orbitals and linear in shape
May 2011
Q 4 Rewrite the following statements after correcting the underlined words:
1. Covalent compounds are characterized by their ability to conduct the electric current. Aug.
97
2. An element has atomic number 8, when two atoms of the element are bound together, the
bond between the resultant molecule will be ionic
Aug. 98
3. Hybridization of carbon atom in ethylene molecule is of the type sp3
Aug. 2000
4. Water has a high boiling point, in spite of its low molecular weight, due to the presence of
coordinate bond between oxygen and hydrogen
Aug. 2001
5. The number of valency electrons in the metal atom plays an important role in the strength of
the ionic bond.
May2004
6. Kosel and Lewis proposed the valence bond theory
Aug.2004
Q5 Complete the following statements after correcting the underlined word(s):
1. Sigma bond is formed by the overlapping the atomic orbitals side by side and the overlapped orbitals
are ------------------- Aug. 2005
Q Compare between:
1.
Covalent bond and coordinate bond.
Aug.96
Q6 Give reason for the following:
1. Aluminum (13Al) is more hard and has a higher melting point than sodium (11Na) although both
are metals.
May96, Aug. 98, Aug. 2001, May2005
2. The bond in hydrogen molecule is pure covalent while in a hydrogen chloride molecule is polar
covalent.
Aug. 2002
3. The angle between hybridized orbitals sp, sp in C2H2 molecule is 180
4. There is no free proton in the solution?
May 2006
May 2007
Q 7 What is meant by:
1. Hybridization.
2. Coordinate bond.
May96
Aug. 97, May2001, Aug. 2005
Q8 Explain the type of bond between X11 & Z17
Aug.95
Q9 What is the difference between each of the following:
1. Hybridization of carbon atoms in ethylene and acetylene molecules.
1. Sigma bonds and p bonds.
May 99 & May2000
Q10 Put the sign (  ) in front of right sentences and the sign (x) in front of the wrong sentences of the
following:
1. All bonds in the hydronium ion are ionic bonds. ( )
May2001
2. A covalent bond is formed when the electron cloud, produced from the sharing of the free
valence electrons, binds the positive ions together in the crystal lattice.
May2003.
3. In the acetylene molecule, each of the two carbon atoms is sp hybridized.
Q 11What is the role of each of the following:
Aug. 2003
The number of valence electrons in the strength of metallic bond.
Aug. 2005
Q12 Write the scientific expression for each of the following statements:
1. A bond formed when the electron cloud of free valence electrons are associated around
positive metal ions.
May 2002
2. Break down of chemical bonds of the reacting molecules and formation of new bonds in the
products.
Aug. 2002
3. A chemical bond which is formed between two atoms as a result of donating a lone pair of
electrons by one atom to another which contains a vacant orbital ready to accept this electron
pair.
May2003
4. The positive ion formed when a water molecule combines with a hydrogen ion and exhibits an
acidic reaction on litmus.
May2003
5. The formation of covalent bond by the overlap of an atomic orbital of an atom which contains
a single electron with an atomic orbital of another atom which contains a single electron also.
Aug. 2003
6. A bond usually formed between metals and nonmetals.
Aug. 2004
7. A bond which is formed as a result of the overlap of two atomic orbitals side by side.
May2005
8. A number that refers to the electric charge (positive or negative) that the atom would have in
the compound, ionic or covalent
Aug 2006
Q13: May 2010
A,B, C and D are four elements with atomic numbers 1,6, 17 and 19 respectively:
May 2010
1.
Which block does (C) and (D) belong to ?
2.
Using these elements, how can you form :
(ionic bond – pure covalent bond – polar covalent bond)
3.
Mention the name of the chemical compound produced and the type of
hybridization when:
two atoms of (B) combine with four atoms of (A)
4.
Mention the number and type of bonds in ammonium chloride
2011
May