Key Stage 3 Science Book 3 Assessments
Obtaining Useful Materials (Purple level)
Answers
1. Which gas is produced when a metal carbonate is decomposed by heating? [1 mark]
d)
Difficulty level: moderate
Skill level: knowledge
2. Which of these metals is extracted from its ores by electrolysis? [1 mark]
d)
Difficulty level: difficult
Skill level: knowledge
3. Why is limestone added to a blast furnace? [1 mark]
c)
Difficulty level: moderate
Skill level: knowledge
4. Which metal cannot be obtained by heating its ores with carbon? [1 mark]
a)
Difficulty level: difficult
Skill level: knowledge
5. Zinc sulfide is roasted in air to produce zinc oxide. Zinc is extracted by heating zinc oxide with carbon.
Which of the following is not produced during this process? [1 mark]
b)
Difficulty level: moderate
Skill level: application
6. Copper pyrites contains copper sulfide. What must it be changed into before the copper can be
extracted using carbon? [1 mark]
b)
Difficulty level: moderate
Skill level: knowledge
© HarperCollinsPublishers 2014
Key Stage 3 Science Book 3 Assessments
7. Place the steps in order, 1-4, to describe what happens during photosynthesis. [1 mark]
Green leaves absorb energy from the Sun
1
Bonds in carbon dioxide and water are broken
2
New but slightly weaker bonds are made
3
Glucose and oxygen are formed
4
Difficulty level: moderate
Skill level: application
8. Match the energies of bond breaking and bond making to the descriptions. [1 mark]
Breaking reactant bonds = 500 kJ/mol; making product bonds = 2000
kJ/mol
Highly exothermic
Breaking reactant bonds = 600 kJ/mol; making product bonds = 800
kJ/mol
Slightly exothermic
Breaking reactant bonds = 1500 kJ/mol; making product bonds = 400
kJ/mol
Highly endothermic
Breaking reactant bonds = 900 kJ/mol; making product bonds = 800
kJ/mol
Slightly
endothermic
Difficulty level: difficult
Skill level: application
9. Which two applications might ceramics be useful for? [1 mark]
a), c)
Difficulty level: moderate
Skill level: application
10. Which two sentences describe the enzyme catalase? [1 mark]
a), c)
Difficulty level: difficult
Skill level: knowledge
11. Name two types of natural polymer found in plants. [2 marks]
(the answer should contain the following)
1) Proteins (also accept DNA as an answer)
2) Cellulose
Difficulty level: moderate
Skill level: knowledge
© HarperCollinsPublishers 2014
Key Stage 3 Science Book 3 Assessments
12. Describe two problems with the manufacture of ceramics. [2 marks]
(the answer should contain two of the following)
1) Defects may be found in the product
2) It is often expensive
3) Ceramics are brittle and often shatter on impact
Difficulty level: difficult
Skill level: knowledge
13. What are the raw materials needed to make concrete? [2 marks]
(the answer should contain two of the following)
1) Limestone is needed to make cement
2) Cement is mixed with sand, gravel and water to make concrete
Difficulty level: moderate
Skill level: knowledge
14. Scientists are trying to make a new synthetic polymer. It must have specific properties. What are the
main things they can vary? [2 marks]
(the answer should contain two of the following)
1) The monomer used (some students might know that two or more monomers are sometimes used)
2) The length of the chain
3) Cross-linkages between chains
Difficulty level: difficult
Skill level: application
15. Why is the ease of thermal decomposition of metal carbonates important in metal extraction? [2
marks]
(the answer should contain the following)
1) Many metals exist as carbonate ores
2) Carbonate ores must be changed into metal oxides prior to extraction
Difficulty level: moderate
Skill level: evaluation
16. Tennis rackets used to be made of wood. Why are they are usually made of carbon fibre nowadays?
[2 marks]
(the answer should contain the following)
1) The rackets are stronger and lighter
2) They do not bend or warp over time
Difficulty level: difficult
Skill level: application
© HarperCollinsPublishers 2014
Key Stage 3 Science Book 3 Assessments
17. This is a diagram of a froth flotation tank:
Froth flotation is used in the extraction of some metals. What happens in the process is that ground up
ore, oil and water are pumped into the tank. Air is pumped in and the particles of metal gather in the
froth on top of the tank. Explain why this process is used in the mining industry. [4 marks]
(the answer should contain the following)
1) It is used to concentrate metal ores
2) It enables metal to be extracted that could otherwise be lost
3) It reduces the amount of metal that has to be discarded, thus making the process more efficient
4) Reducing the amount of metal discarded reduces contamination of the environment
Difficulty level: moderate
Skill level: evaluation
18. Precious metals are often recycled from discarded computers. The processes involve sorting and
separating, dissolving in suitable acids or other solutions, and electrolysis. What affect might this have
on the environment?
[4 marks]
(the answer should contain the following)
1) It avoids mining and processing ores needed to extract the metals, so preserve supplies
2) The chemicals used to dissolve and separate metals from other materials are likely to be hazardous
3) Electricity is needed for electrolysis and this has to be generated in power stations which may pollute
the atmosphere
4) There may be dangers associated with the disposal of waste from the sorting, separation and metal
extraction processes
Difficulty level: difficult
Skill level: application
© HarperCollinsPublishers 2014