Forming the atmosphere - Eduqas

1

Which of the following gases was present in the smallest amounts in the early atmosphere?

2

What process is thought to have formed the early atmosphere?

3

Which three gases are present in the highest amounts in the modern atmosphere?

4

What proportion of the atmosphere is carbon dioxide gas?

5

Why did the proportion of carbon dioxide drop when the Earth started to cool?

6

What was responsible for the historical increase in oxygen in the atmosphere?

7

What is 'potable water'?

8

Why is drinking water chlorinated?

9

The treatment of waste water produces a sludge as a by-product. What is this sludge used for?

10

Which process can be used to make drinking water from seawater?