Download Questions - SMK Raja Perempuan Ipoh

1
CHAPTER 2:THE STRUCTURE OF THE ATOM
2.1 MATTER: (refer text book pg 11)
1. Particle Theory of Matter : Matter is made up of …………………… and ………………..
particles.
2. The tiny particles may be atoms, ……………….. and ……………………….
3. Kinetic Theory of matter : Matter consists of small particles that always collide among each
other. The particles move faster when energy is ……………… and slower when they are
………….
4. Change of states of matter based on Kinetic Theory:
State of matter
Solid
Liquid
Gas
Particles
The particles are
The particles are
The particles are
arrangement
…………….together
………… but not in
…………….. apart from
in an …………….
………….
each other.
Particles can only
Particles can ………,
Particles can ………….,
…………..and ……..
………… and ……….
……………… and
About their fix
throughout the liquid
……… freely
Draw the particles
arrangement
manner
Particles movement
positions
Attractive forces
Very …………………,
Strong ………………
…………………. Forces
between the
…………….. between
between particles but
between particles
particles
particles
then the forces in
solid.
Kinetic energy of
particles
……………………..
……………………….
1
………………………
2
5. When heat energy is supplied to particles in matter, its kinetic energy (increased/decreased)
and the particles in matter vibrate ( faster/ slower) When matter loses heat energy, the
kinetic energy of the particles (increased/decreased) and they vibrate ( faster/ slower).
6.
(
A
)
(
SOLID
B
)
LIQUID
(
C
)
GAS
(
D
)
A …………………… B ……………………… C…………………… D…………………….
7. The temperature at which a ………………………………. Completely changes to
become a liquid is called ………………………………..
8. Explanation on the heating process of matter (refer text book 15)
Temperature OC
D
B
C
A
point
Times/s
States of matter
explanation
A to B
B to C
C to D
2
3
9. Explanation on the cooling process of matter
Temperature OC
A
B
C
D
Times/s
Point
State of matter
Explanation
P to Q
Q to R
R to S
Freezing point : The temperature at which a …………………… changes into …………….
During the freezing process, the temperature remains unchanged because the heat lost to the
environment is ………….. by the heat released when the liquid particles rearrange themselves
to become solid.
3
4
2.2 THE ATOMIC STRUCTURE
The Historical Development Of Atomic Models
Complete all the blanks and draw the structure of each atomic model.
Model
Structure
Characteristic
Dalton’s atomic model
(proposed by
………………in
…………)
The atom was imagined as a small
indivisible ball similar to a very tiny ball.
J.J Thomson discovered the………., a
negatively-charged particle.
The atom was describe as a sphere of
positive charge embedded with electrons.
Thomson’s atomic
model
(proposed by
………………
in………..)
Ernest Rutherford discovered ………, a
positively-charged particle in an atom.
The central region of atom has a very small
positively-charged
……………,
which
contains almost all the mass of the atom.
Rutherford’s atomic
model
(proposed by
………………… in
……….)
The electrons in an atom move in …………
around the nucleus which contains protons.
Bohr’s atomic model
(proposed by
……………… in
………..)
Chadwick
proved the existence of
……………., the neutral particle in the
nucleus.
The nucleus of the atom contains protons &
neutrons, and the nucleus is surrounded by
electrons.
…………… contribute approximately to half
the mass of an atom.
Chadwick’s atomic
model
(proposed by
…………..……. in
……….)
4
5
Subatomic Particle Of An Atom
Fill all the blanks and complete the table. (refer text book pg 18)
1.
Atoms are made up of subatomic particles namely …………….., …………… and …………..
………….. and …………….. are found in the nucleus of an atom while electrons surround the
nucleus.
Subatomic particle
Symbol
Relative mass
Relative electric
charge
Proton
Neutron
Electron
2.
The proton number of an element is the number of ………………… in its atom.
PROTON NUMBER, Z = NUMBER OF. PROTON
3.
Protons and neutrons are collectively called nucleons.
The nucleon number of an element is the total number of ……………… and
…………….. in its atom.
NUCLEON NUMBER, A = NUMBER OF. PROTON + NUMBER OF NEUTRON
4.
The nucleon number is also known as the mass number.
NUMBER OF NEUTRON = NUCLEON NUMBER -- PROTON NUMBER
=
A
-- Z
5. Symbols Of Elements
The standard representation for an atom of any element shows the proton number and the
nucleon number of the element. It can be written as follows:
A
Z
#
X
A – Nucleon number
Z – proton number
X – symbol of element
5
6
1
H
1
3
Li
7
21
Sc
45
Proton number
Nucleon number
2
He
4
4
Be
9
5
B
11
6
C
12
7
N
14
8
O
16
9
F
19
10
Ne
20
11 12
Na Mg
23 24
13
Al
27
14
Si
28
15
P
31
16
S
32
17
Cl
35
18
Ar
40
19
K
39
20
Ca
40
21
Sc
45
Consider part of the periodic table of the element above and complete the table below.
Element
Symbol
Proton
number
No. of
electron
Scandium
Aluminium
Argon
Beryllium
Boron
Calcium
Carbon
Chlorine
Fluorine
Helium
Hydrogen
Lithium
Magnesium
Neon
Nitrogen
Oxygen
Phosphorus
Potassium
6
Nucleon
number
No. of
neutron
Standard
representation
7
2.3 ISOTOPES AND THEIR IMPORTANCE
2.1
Isotopes And Their Importance ( refer text book pg 20)
** Isotopes are atoms of the same element with different numbers of neutrons.
Complete the table:
Element
Hydrogen
Oxygen
Number of
isotopes
3
3
Symbol of
isotopes
H
Number of
protons
1
H
1
H
1
O
8
1
1
1
1
1
1
16
8
Number of
electrons
Number of
neutrons
Name of
isotopes
Hydrogen-2
8
8
9
6
7
8
Oxygen-16
18
8
O
Carbon
6
6
3
Carbon-12
14
6
C
Chlorine
Bromine
2
35
17
Cl
2
* Uses of isotopes in Our Daily Lives
17
17
35
35
20
35
Bromine-80
Bromine-81
(refer text book pg 21)
1. Cobalt-60 : _____________________________________________________
.
2. Gamma rays of Cobalt-60 : ________________________________________
3. Carbon-14 : ______________________________________________________
4. Phosphorus-32 : __________________________________________________
2.4 THE ELECTRONIC STRUCTURE OF AN ATOM
1. The elektron are filled in specific shells. Every shell can be filled only with a certain
number of electrons. For the elements with proton number 1-20:First shell can filled with a maximum of ……………. electrons
Second shell can filled with a maximum of ……………. electrons
Third shell can be filled with a maximum of …………….electrons
7
8
Third shell filled with 8 electrons
Second shell filled with 8 electrons
First shell with 2 electrons
Lithium Atom
Number of proton
1
x
Li
x
3
Number of electron
Number of neutrons
Proton number
Nucleon number
x
Electron arrangement
Sodium Atom
x
Na
x x
11
x
x
x
Number of proton
23
Number of electron
Number of neutrons
x
Proton number
x
Nucleon number
Electron arrangement
x x
x
x
2. Valance electron : Electron in the …………………. shell of a neutral atom.
8
9
CHAPTER 3: CHEMICAL FORMULAE AND EQUATIONS
3.1 RELATIVE ATOMIC MASS (RAM) AND RELATIVE MOLECULAR MASS (RMM)
Relative atomic mass of an elemant , Ar
= The average mass of an atom of the element
1/12 x the mass of an atom of carbon-12
Example:
Ar of C=12
Ar of O=16
Ar of Mg=24
Relative molecular mass of a substance, Mr
= The Average mass of a molecule of the substance
1/12 x the mass of an atom of carbon-12
Calculating Relative molecular mass,Mr
Mr= The sum of Ar of all atoms present in one molecule
Example:
2 Hydrogen
atoms
Molecular
formula
Mr of Water, H2O = 2(1) + 16 = 18
Relative atomic mass
for Oxygen
Relative atomic mass
for Hydrogen
Mr of Carbon dioxide, CO2 = 12 + 2(16) = 44
For ionic substance , Relative formula mass , Fr
= The sum of Ar of all atoms present in the formula
All Ar, Mr and
Fr have no unit
Example:
Fr of Magnesium oxide, MgO = 24 + 16 = 40
Fr of Sodium chloride, NaCl = 23 + 35.5 = 58.5
1. Calculate the Relative molecular masses of the substances in the table below.
Substance
Molecular formula
Relative molecular mass, Mr
Hydrogen gas
H2
2(1) = 2
Propane
C3H8
9
10
Ethanol
C2H5OH
Bromine gas
Br2
Methane
CH4
Glucose
C6H12O6
Ammonia
NH3
[Relative atomic mass : H,1; C,12; O,16; Br,80 ; N,14 ]
2. Calculate the relative formula masses of the following ionic compounds in the table.
Substance
Compound formula
Relative formula mass, Fr
Potassium oxide
K2O
2(39) + 16 = 94
Aluminium sulphate
Al2(SO4)3
2(27)+3[32+4(16)]=342
Zinc nitrate
Zn(NO3)2
Aluminium nitrate
Al(NO3)3
Calcium carbonate
CaCO3
Calcium hydroxide
Ca(OH)2
Hydrated copper(II)
sulphate
CuSO4.5H2O
Hydrated sodium
carbonate
Na2CO3.10H2O
64 + 32 + 4(16) + 5[2(1) + 16]=250
[Relative atomic mass: O,16; C,12; H,1; K,39 ; Cu,64 ; Zn, 65; Cl, 35.5 ; Al, 27 S,32 ; Ca, 40;
Na,23; N, 14]
10
11
3.2 The Mole and the number of particles
1. To describe the amount of atoms, ions or molecules , mole is used
2. A mole is an amount of substance which contains a constant number of particles
(atoms, ions, molecules which is 6.02 x 1023
3. The number 6.02 x 1023 is called ………………………….. (NA)
4. relationship between number of moles and number of particles (atom/ion/molecules):
x Avogadro Constant
number of moles
number of nmolecules
∻ A vogadro Constant
Number of moles
………….. mol of carbon atoms
Number of particles
3.01 x 1023 atoms of carbon
0.2 moles of hydrogen gas
(i)
(ii)
………………… mol of carbon dioxide
molecules
…………….. molecules of
hydrogen
……………. Atoms of hydrogen
6.02 x 10 23 molecules of carbon dioxide
contains :
…………atoms of C and ……. Atoms of O
3.3 Number of Moles and Mass of Substances
1. Molar Mass :
(a) Molar Mass is the mass of one mole of any substance.
(b) Molar Mass is the relative atomic mass, relative molecular mass and relative
formula mass of a substance in g mol -1
(c) Molar Mass of any substance is numerically equal to its relative mass.
X RAM/RMM/RFM
Number
Of
moles
Mass
in g
∻ RAM/RMM/RFM
11
12
2. Complete the following table.
Element/compound
Copper
Chemical
formule
Cu
RAM/RMM/RFM
RAM= 64
Calculate
(a)Mass of 1 moll
(b) Mass of 2 mol :
(c)Mass of ½ mol:
(d)Mass of 3.01x1023 Cu atoms:
Sodium hydroxide
NaOH
RFM= 40
(a) Mass of 3 mol of sodium
hydroxide
(b) Number of moles of sodium
hydroxide in
20 g
Zinc nitrate
Zn(NO3)2
RFM =
a) Number of moles in 37.8 g of
zinc nitrate:
3.4 Number of Moles and Volume of gas
1. Molar volume of a gas : Volume occupied by one mole of any gas.
2. The molar volume of any gas is 24 dm3 at room conditions and 22.4 dm3 at standard
temperature and pressure (STP)
3. generalization : One mole of any gas always occupies the same volume under the same
temperature and pressure;
Example i) 1 mol of oxygen gas, 1 mol of ammonia gas, 1 mol helium gas and 1 mol sulphur
dioxide gas occupies the same volume of 24 dm3 at room condition
12
13
x 22.4/24 dm3
Number of moles of gas
Volume of gas
∻22.4/24 dm3
Volume of gas (dm3)
Mass in gram
Number of moles
No of particles
Complete the above diagram (Refer to Page 33,34 & 38-Chemistry textbook)
Relative Atomic Mass : Fe = 65, Ca = 40, Cl = 35.5, Mg = 24, H = 1, O = 16, C =12
Avogadro number = 6 x 1023,
The Molecules and the Volume of Gas
1.
What is the volume of 0.3 mole of sulphur dioxide gas at STP?
[Molar volume: 22.4 dm3 mol-1 at STP]
(Ans: 6.72 dm3)
2.
Find the number of moles of oxygen gas contained in a sample of 120 cm3 of the gas
at room conditions.
[Molar volume: 24 dm3 mol-1 at room conditions]
(ans: 0.005 mol)
13
14
3.
Calculate the number of water molecules in 90 g of water.
[Relative atomic mass: H, 1; O, 16. Avogadro constant, NA: 6.02 x 1023 mol-1]
(Ans; 3.01x 1024 molecules)
4.
What is the volume of 24 g methane at STP?
[Relative atomic mass: H, 1; C, 12. Molar volume: 22.4 dm3 mol-1 at STP]
(Ans: 33.6 dm3)
5.
How many aluminium ions are there in 20.4 g of aluminium oxide?
[Relative atomic mass: O, 16; Al, 27. Avogadro constant, NA: 6.02 x 1023 mol-1]
6.
Calculate the number of hydrogen molecules contained in 6 dm3 of hydrogen gas at
room conditions.
[Molar volume: 24 dm3 mol-1 at room conditions Avogadro constant, NA: 6.02 x 1023
mol-1]
7.
Find the volume of nitrogen in cm3 at STP that consists of 2.408 x 1023 nitrogen
molecules.
[Molar volume: 22.4 dm3 mol-1 at STP. Avogadro constant, NA: 6.02 x 1023 mol-1]
(2 x 0.2 x 6.02 x1023)
(Ans: 1.505x1023 molecules)
(Ans: 8.96 dm3 )
14
15
3.5 CHEMICAL FORMULAE
1. Chemical formulae- A set of chemical symbols for atoms of elements in whole numbers
representing chemical substances.
Chemical subtance
Chemical formulae
Notes
-------------
2 atoms of H combine with 1 atom of O
------------
NH3
----- atoms of H combine with 1 atom of N
Propene
C3H8
3 atoms of C combine with ----- atom of H
Water
1. There are two types of chemical formulae
** Empirical Formula 
** Molecular Formula 
Molecular formula = (Empirical formula)n
Remember:
Example:
The simplest whole number ratio of atoms of each element
in the compound.
The actual number of atoms of each element that are
present in a molecule of the compound
Compound – Ethene
Molecular formula - C2 H 4
Compound – Glucose
Molecular formula - C6 H12O 6
Empirical formula - CH 2
Empirical formula - CH 2O
2. To find the empirical formula of a compound
Example of calculation:
a) When 11.95 g of metal X oxide is reduced by hydrogen, 10.35 g of metal X is
produced. Find the empirical formula of metal X oxide [ RAM; X,207; O,16 ]
Element
X
O
Mass of element(g)
10.35
11.95-10.35
Number of moles of atoms
10.35÷207
(11.95-10.35)÷16
Ratio of moles
Simplest ratio of moles
Empirical formula : ……………
15
16
b) A certain compound contains the following composition:
Na 15.23%, Br 52.98% , O 31.79%, [ RAM : O, 16; Na, 23; Br,80]
(Assume that 100g of substance is used)
Element
Na
Br
O
Mass of element(g)
15.23
52.98
31.79
Number of moles of atoms
15.23 ÷23
52.98÷80
31.79÷16
Ratio of moles
Simplest ratio of moles
Empirical formula:
Compound
Molecular Formula
Water
H2O
Carbon Dioxide
CO2
Sulphuric Acid
H2SO4
Ethane
C2H4
Benzene
C6H6
Glucose
C6H12O6
Empirical formula
Value of n
CO2
CH2
a) 2.58g of a hydrocarbon contains 2.16 g of carbon. The relative molecular mass of the
hydrocarbon is 86. [RAM H,1; C,12]
i.
ii.
Find the empirical formula of the hydrocarbon
Find the molecular formula of the carbon.
16
17
3. Chemical Formula for ionic compounds:
*Memorise… The formulae of some common cations and anions :
Cation
Formula
Anion
Formula
Hydrogen ion
H
Flouride ion
F
Lithium ion
Li 
Chloride ion
Cl 
Sodium ion
Na 
Bromide ion
Br 
Potassium ion
K
Iodide ion
I
Magnesium ion
Mg 2
Hydroxide ion
OH 
Calcium ion
Ca 2
Nitrate ion
NO3
Barium ion
Ba 2
MnO4
Copper(II) ion
Cu 2
Manganate(VII)
ion
Ethanoate ion
CH 3COO 
Iron(II) ion
Fe 2
Oxide ion
O 2
Iron (III) ion
Fe3
Sulphate ion
SO4
Lead (II) ion
Pb 2
Sulphide ion
S 2
Zinc ion
Zn 2
Carbonate ion
CO3
Chromium (III) ion
Cr 3
Cr2O7
Aluminium ion
Al 3
Dichromate (VI)
ion
Phosphate ion
Ammonium ion
NH 4
Silver ion
Ag 

17
PO4



2
2
3
18
a) Chemical formula of an ionic compound comprising of the ions Xm+ and Yn- is
constructed by exchanging the charges of each element. The formula obtained
will XnYm
example : Sodium oxide
Na+
+1
Copper (II) nitrate
O2-2
2
1
Cu2+
2+
NO3-1
1
2
= Na2O
= Cu(NO3)2
Construct a chemical formula for each of the following ionic compounds:
(a). Magnesium chloride
sulphate
(b). Potassium carbonate
(c). Calcium
(d). Copper (II) oxide
(e). Silver nitrate
(f). Zinc nitrate
(g). Aluminium oxide
(h). Iron(II) hydroxide
(i). Lead(II) sulphide
3.6 CHEMICAL EQUATIONS
Example:
C (s) + O2 (g)  CO2 (g)
Reactant
product
*Qualitative aspect of chemical equation:
1.
2.
3.
4.
Arrow in the equation  the way the reaction is occurring
Substances on the left-hand side  reactants.
Substances on the reight-hand side  products.
State of each substance  solid : (s), liquid (l), gas (g) and aqueous reaction (aq)
Example:
2 H 2 (g)
+ O2 (g)

18
2 H 2O (l)
19
2 molecules
Or
2 mol
1 molecule
or
1 mol
2 molecules
or
2 mol
* Quantitative aspect of chemical equations
1. Coefficients in a balanced equation  the exact proportions of reactants and products
in a
equation.
Write a balanced equation for each of the following reactions and interpret the equations
quantitatively.
(a). Carbon monoxide gas + oxygen gas  carbon dioxide gas
______________________________________________________________________
Interpreting:
___________________________________________________________________
(b). Hydrogen gas + nitrogen gas  ammonia gas
______________________________________________________________________
Interpreting:
___________________________________________________________________
(c). Aluminium + Iron (III) oxide  aluminium oxide + Iron
______________________________________________________________________
Interpreting:
___________________________________________________________________
** Numerical Problems Involving Chemical Equations
Hydrogen peroxide decomposes accordin to the following equation:
2 H 2O2 (l)  2 H 2O (l) + O2 (g)
1. Calculate the volume of oxygen gas, O2 measured at STP that can be obtained
from the decomposition of 34 g of hydrogen peroxide, H 2O2 .
[Relative atomic mass : H, 1 ; O, 16. Molar volume : 22.4 dm 3 mol 1 at STP]
(Ans: 11.2 dm3)
2.Silver carbonate Ag2CO3 breaks down easily when heated to produce silver metal
2 Ag2CO3(l)
4 Ag (s) + 2 CO2 (g) + O2
Find the mass of silver carbonate that is required to produce 10 g of silver
[Relative atomic mass: C, 12 ; O, 16 ; Ag, 108]
19
20
(Ans : 12.77g)
3. 16 g of copper (II) oxide, CuO is reacted with excess methane, CH 4 . Using the
equation below, find the mass of copper that is produced.
[Relative atomic mass : Cu, 64 ; O, 16]
4 CuO (s) + CH 4 (g)  4 Cu (s) + CO2 (g) + 2 H 2O (l)
(Ans : 16 g)
4.A student heats 20 g of calcium carbonate CaCO3 strongly. It decomposes according
to the equation below:
CaCO3 (s)
CaO (s) + CO2 (g).
(a). If the carbon dioxide produced is collected at room conditions, what is its volume?
(b). Calculate the mass of calcium oxide, CaO produced.
[Relative atomic mass: C, 12 ; O, 16; Ca, 40. Molar volume : 24 dm3 mol 1 at room
conditions]
(Ans : (a). 4.8 dm
20
3
(b) 11.2 g)
21
CHAPTER 4 : PERIODIC TABLE of ELEMENTS
4.1 THE PERIODIC TABLE OF ELEMENTS
Historical Development of the Periodic Table
Arrangement of elements in the Periodic Table
a) Elements are arranged in an increasing order of proton number
b) Vertical columns are called group ( Group 1  18)
c) Horizontal rows are called period ( Period 1  7)
d) Elements with similar chemical properties are placed in the same group
e) The group number of the elements with 1 to 2 valence electrons
= the number of valence electrons in its atom.
f) The group number of the elements with 3 to 8 valence electrons
= the number of valence electrons in its atom + 10
g) The period number of an element = the number of shells occupied with electrons
in its atom.
1. Complete the table below
Element
Electron
arrangement
Number of
valence
electrons
Group
Number of
shells
occupied
Period
Element
1
1
H
4
2
He
7
3
Li
9
4
11
5
Be
B
2.1
12
6
C
14
7
N
16
8
O
2.4
19
9
F
20
10
Ne
2.7
2
8
14
17
2
2
23
11
Na
Electron
2.8.1
arrangement
Number of
valence
electrons
Group
1
Number of
shells
occupied
Period
24
12
Mg
27
13
Al
28
14
31
15
Si
P
32
16
S
35.5
17
Cl
40
18
Ar
39
19
K
40
20
Ca
6
16
3
2
4
2.An atom of element E has 10 neutrons. The nucleon number of element E is 19. In
which group and period is element E located in the Periodic Table?
3. An atom of element G has 3 shells occupied with electrons. It is placed in group
21
22
17 of the Periodic Table. What is the electron arrangement of atom G?
4.2 Group 18 Element
known as noble gases: Helium, neon, argon, krypton, xenon & radon
monoatomic
all noble gases are inert – chemicallt unreactive
** The electron arrangement of noble gases are very stable because the
outermost occupied shells are full
Uses of Group 18 elements:
1. Helium gas – to fill airships and weather balloons
2. Neon gas – used in advertising lights and television tubes
3. Argon gas – to fill light bulbs
4. Krypton gas – used in lasers to repair the retina of the eye
5. Radon gas – treatment of cancer
6. Xenon gas – used for making electron tubes and stroboscopic lamps
4.3 Group 1 Elements (Alkali Metals)
Lithium, sodium, potassium, rubidium, caesium & francium
uses of Group 1 elements:
a) Lithium – batteries in calculator, watches and cameras
b) Sodium - Na2 CO3 in soda-lime glass
c) Potassium - KNO3 as fertiliser.
* physical properties: softmetals, low densities, low melting & boiling points,
silvery and shiny surfaces, good conductors of heat and electricity
*Chemical Properties of Group 1 Elements
1. react vigorously with water to produce alkaline metal hyrdroxide solutions and
hydrogen gas
Example: 2Li + 2H 2 O  2LiOH + H 2
Write down the balanced equation when potassium reacts with water
_______________________________________________________________
2. react (burn) in oxygen gas rapidly to produce white solid metal oxides
Example: 4Li + O2  2Li2 O
Write down the balanced equation when rubidium reacts with oxygen
_______________________________________________________________
3. burn in chlorine gas Cl2 , to form white solid metal chlorides.
Example: 2Na + Cl2  2NaCl
Write down the balanced equation when potassium reacts with chlorine gas
_______________________________________________________________
**
The reactivity of Group 1 elements increases when going down the group.
Explain why.
22
23
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
**
Potassium reacts more vigorously with water as compared to sodium. Explain.
(Proton number: Na, 11 ; K, 19)
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
(refer text book pg 67&68)
To Investigate The Chemical Properties of Lithium, Sodium & Potassium
(A) The Reaction of alkali metals With Water, H 2 O
Problem Statement: How does the reactivity of Group 1 elements change when
they react with water?
Hypothesis:
When going down Group 1, alkali metals become more
reactive in their reactions with water.
Variables:
Manipulated variable – Different types of alkali metals
Responding variable – Reactivity of metals
Fixed variables – water, size of metals
Procedure:
(refer to practical book pg 39)
Data & Observation (complete this table!)
Alkali metal
Lithium
Sodium
Potassium
(B)
Observation
The Reaction of alkali metals With Oxygen, O2
(This procedure also can be used to test the reaction of alkali metals with chlorine gas!)
Problem Statement: _________________________________________________
_________________________________________________
Hypothesis:
___________________________________________________
___________________________________________________
Variables:
Manipulated variable – ________________________________
Responding variable – ________________________________
Fixed variables – ____________________________________
Procedure;
(refer practical book pg 36)
Data & Observation (This reaction of alkali metals with chlorine gas will give the same
observations!)
23
24
Alkali metal
Lithium
Sodium
Potassium
Observation
Based on your results, arrange the alkali metals in ascending order of
reactivity.
_______________________________________________________________
Write the chemical equations for the reactions between the products from the
combustion of each alkali metal with water.(refer text book pg 67)
1. ____________________________________________________________
2. ____________________________________________________________
3. ____________________________________________________________
4.4 Group 17 Elements (Halogens)
Fluorine, chlorine, bromine, iodine and astatine
uses of Group 17 elements:
1) Chlorine – water treatment, bleaching agent
2) Bromine – weaker bleaching agent
3) Iodine – needed in human thyroid gland to produce hormones
*Physical properties: Low melting and boiling points.
Fluorine: pale yellow gas
Chlorine: greenish-yellow gas
Bromine: reddish-brown gas
Iodine: purplish-black gas
*Remember
melting and
Cl2
Br2
I2
colour of
Density
boiling points
halogens
increases
increase
becomes
darker
When going down the Group 17, the melting and boiling points increase. Explain
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
(refer text book pg 70)
** Chemical Properties of Group 17 Elements
1. react with water to form two acids
Example: Cl2 + H 2 O
+
HCl
hydrochloric
acid
HOCl
hypochlorus
acid
Write a balanced equation when bromine reacts with water.
__________________________________________________________________
2. in gaseous state react with hot iron to form a brown solid, iron (III) halides.
Example: 2 Fe + 3Br2 
2FeBr3
24
25
Write a balanced equation when iodine vapour reacts with iron
__________________________________________________________________
3. react with sodium hydroxide solution, NaOH , to form sodium halide, sodium
halite (I) and water
Example: I 2 + 2NaOH  NaI + NaOH + H 2 O
Write a balanced equation when chlorine reacts with sodium hydroxide solution
__________________________________________________________________
The reactivity of Group 17 elements decreases when going down the group. Explain
why.
___________________________________________________________________
___________________________________________________________________
________________________________________________________________
Chlorine gas reacts more vigorously with hot iron as compared to bromine gas.
Explain (Proton number: Cl, 17 ; Br, 35)
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
_______________________________________________________________
(refer text book pg 71)
To investigate the Chemical properties of Group 17 elements.
The Reaction of halogens with iron (refer practical book pg 44)
Data and Observation (Complete this form)
Halogens
Observation
Chlorine
Bromine
Iodine
Based on your results, arrange the halogens, Cl2 , Br2 , I 2 in ascending order of
reactivity.
__________________________________________________________________
Element E is placed below element D in Group 17 of the Periodic Table.
(a). Compare the melting and boiling points of element D with element E. Explain
your answer
25
26
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
(b). Write an equation for the reaction between element D and hot iron
_______________________________________________________________
4.5 Elements In A Period (refer text book pg 73)
Example: Period 3 in the Periodic Table – Properties of Elements
Element
Proton number
Electron
arrangement
Atomic radius
(pm)
Physical state at
room
temperature
Electronegativity
*
Na
11
Mg
12
Al
13
Si
14
P
15
S
16
Cl
17
Ar
18
186
160
143
118
110
104
100
94
Solid
Solid
Solid
Solid
Solid
Solid
Gas
Gas
0.9
1.2
1.5
1.8
2.1
2.5
3.0
-
Across Period 3: (refer text book pg 73)
1. The proton number ________________ by one unit from one element to the next
element
2. All the atoms of elements have _______________ shells occupied with electrons.
3. The number of valence electrons in each atom _______________ from 1 to 8.
4. The physical state at room temperature changes from __________ to ___________
5. The atomic radius (atomic size) of elements ________________.
_________________________________________________________
_________________________________________________________
6. The electronegativity of elements. _______________________
_________________________________________________________
_________________________________________________________
7. The oxides of elements change from basic to acidic properties.
Example:
Na2 O , MgO , Al 2 O3 , SiO2
P4 O10 SO2
Cl 2 O7
Below are some oxides of elements of Period 3.
*Sodium oxide, Na2 O
*Aluminium oxide, Al 2 O3
*Silicon (IV) oxide, SiO 2
*Sulphur dioxide, SO2
26
27
(a). Which of these oxides can react with
(i) dilute nitric acid, HNO3 ?________________________________________
(ii) sodium hydroxide, NaOH solution?_______________________________
(b). Based on your answers in (a), what inferences can you make about the
properties of each of the oxides?
_______________________________________________________________
7
3
Q2
Li ,
12
6
C , 199 F
The above show the symbols of lithium, carbon and fluorine.
(a). Which period in the Periodic Table can you find the three elements? Explain.
_______________________________________________________________
(b). Arrange the three elements in order of increasing atomic size.
_______________________________________________________________
(c). Compare the electronegativity of the three elements. Explain your answer.
_______________________________________________________________
_______________________________________________________________
4.6 Transition Elements
elements from Group 3 to Group 12 in the Periodic Table
all are metals
high melting and boiling points ; high densities
good conductors of heat and electricity.
exhibit three special characteristics:
1. transition elements show different oxidation numbers in their compounds.
Example: Iron:
Copper:
2 oxidation numbers  +2, +3
2 oxidation numbers
27
28
2. transition elements form coloured ions or compounds.
Example: Cu 2+ - blue
Fe2+ - green
MnO4- - purple
CrO42- - yellow
Fe3+ - brown
3. transition elements and their compounds are useful catalysts.
Example: (refer text book 77)
1. Haber process – Manufacture of ___________
Catalyst: iron
2. Ostwald process – manufacture of ______________
Catalyst: __________
3. Manufacture of margarine
Catalyst: _____________
4. Contact process – manufacture of ______________
Catalyst: ___________________
****(Zinc is usually not classified as a transition element because it does not exhibit the
special characteristic of transition elements!)
****(Precious stones such as emerald, rubies, sapphire and jade are beautiful due to the
colours of the transition element compounds present in them!)
28
29
1 Diagram 1.1 shows the atomic structure of elements X and Y.
(Rajah 1.1 menunjukkan struktur atom bagi unsur X dan Y.)
DIAGRAM 1.1
(a) What is the proton number of element X?
(Apakah nombor proton bagi unsur X?)
………………………………………………………….…………………….…………………
[1 mark]
(b) (i)
Atom of element X has isotopes. What is meant by isotopes?
(Atom unsur X mempunyai isotop. Apakah yang dimaksudkan dengan isotop?)
…………………………………………………………………….………………………
[1 mark]
(ii) State one example of an isotope. (Nyatakan satu contoh isotop.)
……………………………………………………………………………………………
[1 mark]
(c)
(i)
Atom of element Y has a nucleon number of 23. Calculate the number of
neutrons in atom Y.
(Atom unsur Y mempunyai nombor nukleon 23. Hitungkan bilangan neutron
bagi atom Y.)
……………………………………………………………………………………………
[1 mark]
(ii) Write the standard representation of atom Y.
(Tuliskan simbol atom unsur Y.)
……………………………………………………………………………………………
[1 mark]
(d) Ethanol is an organic compound. Its melting point is –117 oC and its boiling point is
78 oC .
(Etanol ialah satu sebatian organik dengan takat lebur – 117 oC dan takat didih 78
o
C.)
(i)
What is the physical state of ethanol at room temperature?
(Apakah keadaan fizik etanol pada suhu bilik?)
……………………………………………………………………………..……………
[1 mark]
29
30
(ii)
Draw the arrangement of particles of ethanol at 100 oC.
(Lukiskan susunan zarah etanol pada 100 oC.)
100 oC
[1 mark]
(iii)
State how the movement of ethanol particles changes when heated from room
temperature to 100 oC.
(Nyatakan bagaimana pergerakan zarah-zarah etanol berubah apabila
dipanaskan dari suhu bilik ke 100 oC.)
…………………………………………….………………………………..……………
[1 mark]
(iv)
Sketch the graph of temperature against time when ethanol is heated from
room temperature to 100 oC.
(Lakarkan graf suhu melawan masa apabila etanol dipanaskan daripada suhu
bilik ke 100 oC)
Temperature/oC
Time/min
2 Figure 2.1 shows the chemical symbols which represent elements R, S and T.
(Rajah 2.1 menunjukkan simbol kimia yang mewakili unsur-unsur R, S dan T.)
35
12
39
17
6
19
30
[2 marks]
31
R
(a)
(i)
S
T
FIGURE 2.1
Write the electron arrangement of atom T.
(Tuliskan susunan elektron bagi atom T.)
………………………………………………………………………………...…
[1 mark]
(ii)
State the period and the group for element T in the Periodic Table.
(Nyatakan kala dan kumpulan bagi unsur T dalam Jadual Berkala.)
Period (Kala) : ….……………………………………………………………..
Group (Kumpulan) ………………………………………………….………...
[2 marks]
(b)
Atoms of R and S can react to form a compound.
(Atom R dan atom S boleh bertindak balas untuk membentuk satu sebatian.)
(i)
Name the type of bond in the compound formed between atoms R and S.
(Nyatakan jenis ikatan dalam sebatian yang terbentuk antara atom R dan atom
S.)
…………………………………………………………………………….
[1 mark]
(ii)
Give one physical property of the compound in (b)(i).
(Beri satu sifat fizik bagi sebatian di (b)(i).)
….……………………………………………………………………………
[1 mark]
(c)
Atoms of R and T can also react to form a compound. Draw the electron
arrangement for the compound formed.
(Atom R dan atom T juga boleh bertindak balas untuk membentuk satu sebatian.
Lukiskan susunan elektron bagi sebatian yang terbentuk.)
(d)))
Iron, copper, nickel and chromium are examples of transition elements.
(Ferum, kuprum, nikel dan kromium adalah contoh unsur peralihan.)
[ 2 marks]
31
32
(i)
State the position of transition elements in the Periodic Table.
(Nyatakan kedudukan unsur peralihan dalam Jadual Berkala.)
……………………………………………………………….…….……………
[1 mark]
(ii)
State two special characteristics of transition elements.
(Nyatakan dua ciri istimewa bagi unsur peralihan.)
………………………………………………………………….………………
[2 marks]
3
Diagram 2 shows part of the Periodic Table of the Elements.
U, V, W, X, Y and Z do not represent the actual symbol of the elements.
U
W
V
X
Y
Z
DIAGRAM 2
(a)
Using the letters in the Periodic Table of the Elements in Diagram 2, answer the
following questions.
(i) Choose two elements in period 3
……………………………………………………………………………………………
[1 mark]
(ii) Which element will form coloured compound?
……………………………………………………………………………………………
[1 mark]
(iii) Write the electron arrangement for an atom of element V.
……………………………………………………………………………………………
[1 mark]
(iv) Which element is chemically unreactive ?
……………………………………………………………………………………………
[1 mark]
(v)
Explain your answer in (a)(iv)
……………………………………………………………………………………………
……………………………………………………………………………………………
32
33
[2 marks]
(vi) State one of the uses of U.
……………………………………………………………………………………………
[1 mark]
(b)
When X reacts with cold water, hydroxide solution is formed and a gas is released.
(i) Name the gas
………………………………………….…………………………………………………………
[ 1 mark ]
(ii) Write the chemical equation for the reaction
………………………………………………………………………………………
[ 2 marks ]
33