Key Stage 3 Science Book 1 Assessments
Elements compounds and reactions purple Answers
1. The Periodic Table shows chemical elements. Which one of these statements is true? [1 mark]
d)
Difficulty level: moderate
Skill level: knowledge
2. We can represent the oxidation of magnesium by using the equation:
2Mg + O2 → 2MgO
Which one of these statements is untrue? [1 mark]
a)
Difficulty level: moderate
Skill level: knowledge
3. Why is gold sometimes used in circuit boards? [1 mark]
c)
Difficulty level: moderate
Skill level: knowledge
4. Sulfuric acid has the chemical formula H2SO4. Explain what the formula H2SO4 means. [2 marks]
(the answer should contain the following)
1) Water contains [the elements] hydrogen, sulfur and oxygen
2) Hydrogen, sulfur and oxygen combine in the ratio 2:1:4
Difficulty level: difficult
Skill level: application
5. In Diagrams A, B and C the circles represent two different types of atom. What does Diagram B show? [1 mark]
d)
Difficulty level: moderate
Skill level: application
© HarperCollinsPublishers 2014
Key Stage 3 Science Book 1 Assessments
6. In Diagrams A, B and C the circles represent two different types of atom. What does Diagram C show? [1 mark]
e)
Difficulty level: moderate
Skill level: application
7. Use your Periodic Table to classify these elements as metal, non-metal or metalloid. [1 mark]
Strontium (Sr)
Metal
Manganese (Mn)
Metal
Selenium (Se)
Non-metal
Tellurium (Te)
Metalloid
Uranium (U)
Metal
Difficulty level: moderate
Skill level: application
8. Explain the similarities and differences between these two chemical reactions: magnesium burning and iron
rusting (oxidising). [4 marks]
(the answer should contain any two of the following similarities and any two of the differences)
1) Similarity: Both are a reaction with oxygen
2) Similarity: Both produce a metal oxide
3) Similarity: Both are irreversible changes
4) Similarity: Atoms rearrange in both
5) Similarity: Both magnesium and iron increase in mass by taking oxygen form the air when they react with
oxygen
6) Difference: Magnesium burns at a high temperature but iron rusts at a low temperature
7) Difference: Iron rusting requires water as well as oxygen; magnesium burning only requires oxygen
8) Difference: Magnesium produces magnesium oxide; iron produces iron oxide
Difficulty level: moderate
Skill level: application
© HarperCollinsPublishers 2014
Key Stage 3 Science Book 1 Assessments
9. Overhead pylons carry high voltage electricity around the country. The cables could be made from a bundle of
copper wires (Cable A) or a bundle of aluminium wires with a steel core (Cable B).
What is the main advantage of having copper as the wire (Cable A)? [1 mark]
c)
Difficulty level: moderate
Skill level: evaluation
© HarperCollinsPublishers 2014
Key Stage 3 Science Book 1 Assessments
10. Overhead pylons carry high voltage electricity around the country. The cables could be made from a bundle of
copper wires (Cable A) or a bundle of aluminium wires with a steel core (Cable B).
Cable B is the usual choice for high voltage overhead power cables. Which two statements are good reasons to
choose Cable B? [1 mark]
b), d)
Difficulty level: moderate
Skill level: evaluation
11. The formula of a chemical compound can be modelled using building bricks. Match these diagrams of building
blocks to compounds they model. [1 mark]
Diagram A
Carbon dioxide (CO2)
Diagram B
Copper oxide (CuO)
Diagram C
Methane (CH4)
Diagram D
Aluminium chloride (AlCl3)
Difficulty level: difficult
Skill level: application
© HarperCollinsPublishers 2014
Key Stage 3 Science Book 1 Assessments
12. All models used in science have strengths and limitations.
Identify two strengths and one limitation of using building bricks to model compounds. [2 marks]
(the answer should contain any two of the following strengths and any one of the limitations)
1) Strength: Different colours represent different atoms/elements
2) Strength: Building blocks join together
3) Strength: Building block models show simple ratios
4) Strength: Shows difficult ideas visually
5) Limitation: Atoms are not coloured
6) Limitation: Atoms are spherical
7) Limitation: Atoms are very small
Difficulty level: difficult
Skill level: evaluation
13. Kalgoorlie super pit is the world’s biggest open gold mine. The mine is in Australia and is three kilometres long,
a kilometre and a half wide and 400 metres deep.
Explain the benefits and drawbacks of open cast mining. [4 marks]
(the answer should contain any two of the following benefits and any two of the drawbacks)
1) Benefit: Less dangerous than underground mining
2) Benefit: Provides us with important resources
3) Benefit: The mine can be refilled after mining is finished
4) Drawback: Wildlife and habitats are damaged
5) Drawback: Farmland may be ruined
6) Drawback: People may need to be moved
7) Drawback: Damage to water supplies
8) Drawback: Dust and noise
Difficulty level: moderate
Skill level: knowledge
© HarperCollinsPublishers 2014
Key Stage 3 Science Book 1 Assessments
14. Look at the data table for the group 18 elements (noble gases).
At which of these temperatures could xenon be a liquid? Choose three answers. [1 mark]
b), c), d)
Difficulty level: difficult
Skill level: knowledge
15. Look at the data table for the group 18 elements (noble gases).
How do the density and boiling points of the noble gases change as you go down the group? [1 mark]
b)
Difficulty level: moderate
Skill level: knowledge
16. A group of students reacted magnesium metal in air to make magnesium oxide, MgO. Predict the formula for
calcium oxide. Give a reason for your prediction. [2 marks]
(the answer should contain both of the following)
1) CaO
2) Calcium is likely to react in a similar way to magnesium OR calcium is in the same group as magnesium
Difficulty level: difficult
Skill level: application
17. A group of students reacted magnesium metal in air to make magnesium oxide. The students weighed the
magnesium before the experiment and weighed the mass of magnesium oxide after the experiment. They
repeated the experiment three more times.
Why was it important to repeat the experiment? [1 mark]
b)
Difficulty level: moderate
Skill level: knowledge
© HarperCollinsPublishers 2014
Key Stage 3 Science Book 1 Assessments
18. This apparatus is used to investigate the thermal decomposition of metal carbonates:
Steve’s group used this with a number of different metal carbonates. No matter which they tried, what always
happened in the test tube on the right and why? [4 marks]
Answer to include:
1) Gas bubbled through
2) Lime water went milky …
3) …showing presence of carbon dioxide
4) Whenever metal carbonates thermally decompose they always release carbon dioxide
Difficulty level: moderate
Skill level: knowledge
© HarperCollinsPublishers 2014