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Exam (elaborations)
AQA GCSE CHEMISTRY Foundation Tier Paper 2F June 2021 QP
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---40June 20222020/2021A+
- This question is about the Earth’s atmosphere. box 
0 1 . 1 How long ago was the Earth formed? 
[1 mark] 
Tick () one box. 
4.6 billion years ago 
4.6 million years ago 
4.6 thousand years ago 
Table 1 shows the percentages of gases in the atmospheres of Mars and 
Earth today. 
Table 1 
Gas Percentage of gas in atmosphere (%) 
Mars Earth 
Carbon dioxide 95.97 0.04 
Nitrogen 1.89 78.09 
Oxygen 0.15 20.95 
Other gases 1.99 X 
0 1 . 2 Calculate the percentage X of other gases in the Earth’s ...
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Exam (elaborations)
AQA GCSE COMBINED SCIENCE:TRILOGY Foundation Tier Chemistry paper 2F QP June2021
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---36June 20222020/2021A+
- AQA GCSE COMBINED SCIENCE:TRILOGY Foundation Tier Chemistry 
paper 2F QP June2021 0 1 Fresh water contains low levels of dissolved salts. 
Water reacts with anhydrous copper sulfate in a reversible reaction. 
The word equation for the reaction is: 
water + anhydrous copper sulfate ⇌ hydrated copper sulfate 
0 1 . 1 How does the equation show that the reaction is reversible? 
[1 mark] 
0 1 . 2 Complete the sentences. 
Choose answers from the box. 
[2 marks] 
blue green orange white yellow 
The ...
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