Gr 10 Physical Sciences
Past Paper Booklet
MEMO
1
,Part 1: Chemistry
(June 2018 Q2)
1.1.1 Temperature is the measure of the average kinetic energy of the particles. (2)
1.1.2 Gaseous (1)
1.1.3 5℃ (1)
1.1.4 Condensation (1)
1.1.5 - As the temperature decreases kinetic energy of the molecules decrease. (2)
- Attractive forces between the molecules increase.
1.1.6 Solid (1)
1.2.1 Boiling point is the temperature of a liquid at which its vapour pressure
equals the external (atmospheric) pressure. (2)
1.2.2 Statement b. (3)
- Boiling is the change in phase of a liquid to a gas at a fixed temperature
- Evaporation is the change in phase of a substance from a liquid to a gas
at any temperature.
[13]
(June 2018 Q3)
2.1.1 B (1)
2.1.2 A (1)
2.1.3 Endothermic, in both processes heat energy was added. (2)
2.2 a) Hydrogen bromide (1)
b) Carbon tetrachloride (2)
c) Sodium thiosaphate (2)
2.3 a) 4Fe + 3O2 → 2Fe2O3 (2)
b) 2C2H6 + 7O2 → 4CO2 + 6H2O (2)
c) Na2SO4 + Ba(NO3)2 → BaSO4 + 2NaNO3 (2)
2.4 a) Matter cannot be created or destroyed but it is transformed from one form
to another. (2)
b) Mreactants = 2x1+2x14+2x3x16+40+2x16+2x1 = 160g.mol-1 (3)
Mproducts = 40 + 2x14+ 2x2x16 + 2x2x1 + 2x16 = 160g.mol-1
[20]
(June 2018 Q4)
2
,3.1.1 Atoms of the same element (having the same number of protons), with
different number of neutrons. (1)
3.1.2 Alkali Earth metals (1)
3.1.3 Neon/Ne (1)
3.1.4 N = 26 – 12 = 14 neutrons (1)
3.1.5 %25Mg = 100 – (78,99 + 11,01)
= 10% (1)
𝑀24 𝑀𝑔 𝑥 % 𝑎𝑏𝑢𝑛𝑑𝑎𝑛𝑐𝑒 𝑀25 𝑀𝑔 𝑥 % 𝑎𝑏𝑢𝑛𝑑𝑎𝑛𝑐𝑒 𝑀26 𝑀𝑔 𝑥 % 𝑎𝑏𝑢𝑛𝑑𝑎𝑛𝑐𝑒
3.1.6 R.A.M = + +
100% 100% 100%
23,985 𝑥 78,99 24,959 𝑥 10 25,983 𝑥 11,01
= + +
100% 100% 100%
= 24,302 g.mol-1 (4)
3.2.1 Molecule that consists of 2 atoms from the same element. (2)
3.2.2 2 (1)
3.2.3 The maximum of 2 electrons in an orbital provided that they spin in opposite
directions. (2)
3.2.4 1s22s22p4 (2)
3.2.5 Covalent bond (1)
[17]
(June 2018 Q5)
4.1 An ionic bond is a chemical bond whereby electron(s) are transferred from
one atom to the other. (2)
4.2 a) (2)
b) (2)
[6]
(June 2018 Q8)
5.1 a) Energy needed per mole to remove a mole of electrons from a mole of
atoms in a gaseous phase. (2)
b) As one moves down the group, First ionisation energy decreases. (2)
3
, OR as one moves up the group, First ionisation energy increases
5.2 Na has 1 unpaired electron in the 3s orbital. Mg has a pair of electrons in the
3s orbital. This represents greater stability. Therefore, more energy is needed
in Mg. (3)
5.3 a) Decreases (1)
b) Decreases (1)
[9]
(June 2017 Q2)
6.1 a) Homogenous (1)
b) One element and one compound
Oxygen is made up of the one type of atom.
Water is a chemical combination of different atoms. (3)
6.2.1 Diamond (1)
6.2.2 Iodine (1)
6.2.3 Sodium chloride (1)
6.2.4 Dry ice (1)
6.2.5 Magnesium oxide (1)
[9]
(June 2017 Q3)
7.1.1 B (1)
7.1.2 (2)
7.1.3 A (1)
7.1.4 C (1)
7.2 a) Hydrogen phosphide (2)
b) Zinc chlorate (2)
4
Past Paper Booklet
MEMO
1
,Part 1: Chemistry
(June 2018 Q2)
1.1.1 Temperature is the measure of the average kinetic energy of the particles. (2)
1.1.2 Gaseous (1)
1.1.3 5℃ (1)
1.1.4 Condensation (1)
1.1.5 - As the temperature decreases kinetic energy of the molecules decrease. (2)
- Attractive forces between the molecules increase.
1.1.6 Solid (1)
1.2.1 Boiling point is the temperature of a liquid at which its vapour pressure
equals the external (atmospheric) pressure. (2)
1.2.2 Statement b. (3)
- Boiling is the change in phase of a liquid to a gas at a fixed temperature
- Evaporation is the change in phase of a substance from a liquid to a gas
at any temperature.
[13]
(June 2018 Q3)
2.1.1 B (1)
2.1.2 A (1)
2.1.3 Endothermic, in both processes heat energy was added. (2)
2.2 a) Hydrogen bromide (1)
b) Carbon tetrachloride (2)
c) Sodium thiosaphate (2)
2.3 a) 4Fe + 3O2 → 2Fe2O3 (2)
b) 2C2H6 + 7O2 → 4CO2 + 6H2O (2)
c) Na2SO4 + Ba(NO3)2 → BaSO4 + 2NaNO3 (2)
2.4 a) Matter cannot be created or destroyed but it is transformed from one form
to another. (2)
b) Mreactants = 2x1+2x14+2x3x16+40+2x16+2x1 = 160g.mol-1 (3)
Mproducts = 40 + 2x14+ 2x2x16 + 2x2x1 + 2x16 = 160g.mol-1
[20]
(June 2018 Q4)
2
,3.1.1 Atoms of the same element (having the same number of protons), with
different number of neutrons. (1)
3.1.2 Alkali Earth metals (1)
3.1.3 Neon/Ne (1)
3.1.4 N = 26 – 12 = 14 neutrons (1)
3.1.5 %25Mg = 100 – (78,99 + 11,01)
= 10% (1)
𝑀24 𝑀𝑔 𝑥 % 𝑎𝑏𝑢𝑛𝑑𝑎𝑛𝑐𝑒 𝑀25 𝑀𝑔 𝑥 % 𝑎𝑏𝑢𝑛𝑑𝑎𝑛𝑐𝑒 𝑀26 𝑀𝑔 𝑥 % 𝑎𝑏𝑢𝑛𝑑𝑎𝑛𝑐𝑒
3.1.6 R.A.M = + +
100% 100% 100%
23,985 𝑥 78,99 24,959 𝑥 10 25,983 𝑥 11,01
= + +
100% 100% 100%
= 24,302 g.mol-1 (4)
3.2.1 Molecule that consists of 2 atoms from the same element. (2)
3.2.2 2 (1)
3.2.3 The maximum of 2 electrons in an orbital provided that they spin in opposite
directions. (2)
3.2.4 1s22s22p4 (2)
3.2.5 Covalent bond (1)
[17]
(June 2018 Q5)
4.1 An ionic bond is a chemical bond whereby electron(s) are transferred from
one atom to the other. (2)
4.2 a) (2)
b) (2)
[6]
(June 2018 Q8)
5.1 a) Energy needed per mole to remove a mole of electrons from a mole of
atoms in a gaseous phase. (2)
b) As one moves down the group, First ionisation energy decreases. (2)
3
, OR as one moves up the group, First ionisation energy increases
5.2 Na has 1 unpaired electron in the 3s orbital. Mg has a pair of electrons in the
3s orbital. This represents greater stability. Therefore, more energy is needed
in Mg. (3)
5.3 a) Decreases (1)
b) Decreases (1)
[9]
(June 2017 Q2)
6.1 a) Homogenous (1)
b) One element and one compound
Oxygen is made up of the one type of atom.
Water is a chemical combination of different atoms. (3)
6.2.1 Diamond (1)
6.2.2 Iodine (1)
6.2.3 Sodium chloride (1)
6.2.4 Dry ice (1)
6.2.5 Magnesium oxide (1)
[9]
(June 2017 Q3)
7.1.1 B (1)
7.1.2 (2)
7.1.3 A (1)
7.1.4 C (1)
7.2 a) Hydrogen phosphide (2)
b) Zinc chlorate (2)
4
