Download Models 1 - Mr Khaled Nasr

Chapter 1
Atomic Structure
Question (1)
Choose the correct answer
1- The rays which are deflected towards the positive electrode in an electric field is
a- alpha particle
b- gamma rays
c- cathode rays
d- x- rays
2- If (n) presents the principal energy level, the maximum number of electrons it may take is
equal to -------b-n2
a-n
c- 2n2
d- 2n2
3- The maximum number of electrons in the fifth principal energy level is -----------------------a-32
b-50
c-25
d-5
4- On heating gases or vapours to high temperature under reduced pressure they radiate light
composed of a limited number of colourled lines named ------------ spectra.
a- visible
b- continuous
c- line
d- absorption
5- The total number of orbitals in the principal energy level .(if ((n)) represent the principal
quantum number ) is
b-n2
a-n
d- 2n2
c- 2n
6- The electron configuration for oxgen ( O8 ) in the ground state according to Hund’ s rule is
2
2
3
a-1s 2s 2 p 3s
1
2
1
3
b-1s 2s 2 p 3s
c- 1s 2 2s 2 2 p x2 2 p 1y 2 p z1
1
d - 1s 2 2s 2 2 p x2 2 p y2 2 p z0
7- The electron configuration for an element of atomic number (16) according to Hund’ s rule is
2
2
6
2
4
a- 1s 2 2s 2 2 p 6 3s 2 3 p x2 3 p 1y 3 p z1
b- 1s 2s 2 p 3s 3 p
b- 1s 2 2s 2 2 p 6 3s 2 3 p x2 3 p y2 3 p z0
c- 1s 2 2s 2 2 p 6 3s 2 3 p x2 3 p y2 3 p z1
8- The total number of orbitals on f sublevel is --------------------a-1
b-5
c-3
d- 7
9- The quantum number which indicates the number of energy sublevels within each principal
energy level is the -------------------------- quantum number.
a- magnetic
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b- subsidiary
c- principal
d- spin
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10- When the electrons of an excited atom fall back to lower energy levels, there is an emission
of energy levels that produces -------------------------a- alpha particles
b- beta particles
c- spectral lines
d- gamma radiation
1 1-. An atom has 8 electrons in its (d) sublevel. d- orbitals in this sublevel have single electron
are:
a- 1
b- 3
c- 2
d- 4
12- The electron configuration for carbon ( C6) according to Hund’ s rule is -------------------b- 1s 2 2s 2 2 p 2
a- 1s 2 2s 2 2 p x1 2 p 1y
2
2
2
2
2
2
c - 1s 2s 2 p
d- 1s 2s 2 p
13-The electron configuration for the bromide ion, Br- (Br35) is ----------------------2
9
a - [Ar18 ]4s 3d 4 p
2
10
c- [Ar18 ]4s 3d 4 p
6
2
10
2
9
b- [Ar18 ]4s 3d 4 p
6
5
5
d- [Ar18 ]4s 3d 4 p 5s
1
14- Which electron notation represents the valence electrons of a phosphorus atom [ P15 ] in the
ground state?
abcd15- An element has the atomic number 19 number of orbitals full of electrons is
a-10
b-9
c-3
d-4
16- An atom of element contains 4 principal energy levels which has 5 valence electrons .The
number of electrons in the level before outermost one is -------------------a-18
b-7
c-10
d-8
17- The total number of the completely filled orbitals in nitrogen atom ( 7N ) in its ground state
is -----------a-1
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b-3
c-2
d-5
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18- An atom in the ground state has 7 valence electrons, the electron configuration which
represents the outermost principal energy level of this atom is ----------------------------a- 3s13p6
b- 3s1 ,3p43d2
c- 3s23p5
d- 3s2 3p43d1
19- The principal energy level has a maximum of three sublevels is -----------------a-K
b-M
c-L
d-N
20- The orbital rotation for the electrons in the third principal energy Level of an argon atom
[ Ar18 ] in the ground state is
21- An atom in the ground state has 4 principal energy levels, the forth energy level (valence
energy level ) has 7 electrons .The atomic number of this atom is -----------------------a-35
b-27
c-30
d-26
22- The 6th shell is filled with 32 electrons because this level consists of ------------------ orbitals.
a-32
b-9
c-l6 .
d-36
23- The sublevel (d) is filled with 10 electrons because this sublevel consists of -----------orbitals.
a-3
b-5
c-1
d-7
24- The electron transfers from it original level to 7 M level when absorbs a ---------------- of
energy
a-
1
quantum
2
b- quantum
c- 6 quantum
d- 2 quantum
25- Electrons that exist in the same orbital may be represented by:
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26- The maximum number of electrons that occupies a single orbital of the 3d sublevel is
electrons.
a-l0
b-5
c- 2
d- 4
27-The electron of the highest energy are those of the ------------ sublevel:
a- 4s
b- 4p
c- 4d
d- 4f
28- The total number of orbitals in the principal energy level M is ----------------a- 9
b- 3
c- 5
d- 7
29- The atomic number of sodium ion (Na+) is ---------------a- 10
b- 11
c- 12
d- 9
30- The quantum number that define the number shape and direction of orbitals within a certain
energy sublevel is--a- principal
b- subsidiary
c- spin
d- magnetic
31- The correct electron configuration of Cr (24 Cr ) is -----------------a- [ Ar18] 4s13d5
b- [Ar] 4s23d5
c- [Ar] 4s03d5
d- [Ar] 4s23d4
32- The electron configuration [18 Ar] 3d5 is for ---------------a- Fe+.3
b- Mn+3
c-Cr+2
d-Co+3
Question (2)
Write the scientific expressions of the following statements:
1- The amount of energy absorbed or emitted when an electron jumps from one energy level to
another.
2- A pure substance which can’t be analyzed by the known chemical methods.
3- Number of protons or electrons orbits the nucleus.
4- Sublevel energy contains five orbitals.
5- The electron is a material negatively charged particle which also has wave properties.
6- Electrons occupy the sublevels in order of increasing their energy sublevels are filled first.
7- A number defines the type of spin motion of the electron around its own axis.
8- No electron pairing takes place in a given sublevel until each orbital contains one electron.
9- A number represents the number of orbitals within a certain energy sublevel.
10- A stream of invisible rays emitted from the cathode tube under particular conditions of
pressure and potential difference.
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11- The determination of both the velocity and position of an electron at the same time is
practically impossible.
12- Numbers define the volume of space where there is maximum probability of finding
electrons.
13- The number which Bohr used in explaining the spectrum of the hydrogen atom.
14- An atom gained quantum of energy through heating or electric discharge.
Question (3)
Give reasons for the following:
1- No electron pairing takes place until each orbital contains one electron.
2- The spin motion of single electron must be in the same direction.
3- The electron prefers to be paired with another electron in an orbital than moving to a higher
energy sublevel.
4- Pairing of electrons takes place in one of the orbitals of 2p sublevel in [ 8O] atom however
there is an empty 3s sublevel.
5- The third energy level doesn’t take more than 18 electrons.
6- The maximum numbers of electrons in the fourth energy level is 32 electrons.
7- The atomic number of an element equals 8 therefore the electron configuration for this
element according to Hund’s rule is:
8- Each electron of the sublevel of nitrogen atom ( 7N ) occupies one orbital
9-It is impossible to determine accurately both the velocity and position of an electron
simultaneously.
10- Sublevel d is saturated with 10 electrons while the fifth energy level is saturated with 32
electrons.
11- The maximum number of electrons in an energy level to the fourth Energy level is 2n2
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12- In Rutherford experiment, most of alpha particles penetrate the gold foil? A few particles
were deflected? A few particles even bounced back from the gold foil in the direction from
which they had come?
13- The electron is considered just as a minute negatively charged particle this consideration is
wrong and inaccurate.
Question (4)
Select from column (B) the
suitable statement that
suits it from column (A):
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2-
3-
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Question (5)
Answer the following questions:
1- The electronic configuration for the ground state of chromium is 4s1 3d5. Explain why it
doesn’t agree with the aufbau principle 4s2 3d4?
2- The electronic configuration for the ground state of copper is 4s1 3d10 Explain why it doesn’t
agree with the aufbau principle 4s2 3d10
3- The electronic configuration for the ground state of an element Ais4s24p3
a- What is the atomic number of this element?
b- How many sublevels are occupied by electrons?
c- How many orbitals are occupied by electrons?
d- How many orbitals are half filled?
1
4- The atomic number of Cl is (17). Write the electronic configuration of Cl ,Cl
the ground state.
1
and Cl in
5- The fourth energy level (N) has 4 sublevels
a- What are their names?
b- How many orbitals are there in the fourth shell?
c- How many electrons can occupy the fourth shell?
6- How does the shape of an (s) orbital differ from that of (p) orbital?
Draw the shapes of these kinds of orbitals?
Question (6)
Compare between each of the following:1- The principal quantum number and subsidiary quantum number.
2- Aufbau principal and Hund’s rule.
3- The magnetic quantum number and subsidiary quantum number.
4- The matter waves and electromagnetic waves.
5- Potassium ion (k+) and potassium atom in
a- The atomic number
b- The electronic configuration Question (7)
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Write short account on :1- The advantages of Bohr’s atomic model.
2- The inadequacy of Bohr’s atomic model.
3- Objection on Rutherford’s atomic model to Maxwell’s theory.
4- Properties of cathode rays.
5- Rutherford experiment and its results. Question (8)
Write the most important contribution of every scientist of the following in chemistry:1- Aristotle
2- Jon Dalton
3- Schrodinger
4- Sommerfield
5- Heisenberg
6- Bohr
7- Maxwell
8- Thomson
9- Boyle
10- Rutherford
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