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The Water Cycle
1	How does Water Vapour get into the Air? Give two sources.	Answer
2	What is Precipitation in the Water Cycle?	Answer
3	Why is the Sea Salty?	Answer
4	Give one process which remove Salt from the Sea.	Answer

The Carbon Cycle
5	Give two process which release Carbon Dioxide into the Atmosphere.	Answer
6	Give one process which removes Carbon Dioxide from the Atmosphere.	Answer
7	Does Carbon Dioxide dissolve in Rain Water?	Answer
8	How can Limestone release Carbon Dioxide into the Atmosphere?	Answer

The Nitrogen Cycle
9	What is Fixing?	Answer
10	Why do Plants need Nitrogen?	Answer
11	What type of bacteria turn Nitrite into Nitrate in the Soil?	Answer
12	What type of bacteria turn Nitrate in the Soil into Nitrogen in the Atmosphere?	Answer

The Early Atmosphere
13	Name two Gases which were present in the Earth's early Atmosphere?	Answer
14	Where did the Gases in the Earth's early Atmosphere come from?	Answer
15	Where did the Oceans come from?	Answer
16	What were the First Life Forms?	Answer
17	Which Gas do Green Plants add to the Atmosphere?	Answer
18	Where did Nitrogen in the Earth's Atmosphere come from?	Answer

The Atmosphere Today
19	How is Ozone Produced high up in the Atmosphere?	Answer
20	How does the Ozone Layer Protect our planet?	Answer
21	Name one Chemical which can produce a hole in the Ozone Layer?	Answer
22	Give one risk of having a hole in the Ozone Layer.	Answer
23	What is the Proportion of Nitrogen in the Atmosphere Today?	Answer
24	What is the Proportion of Oxygen in the Atmosphere Today?	Answer
25	What is the Proportion of Argon in the Atmosphere Today?	Answer
26	Which Experiment can show the Proportion of Oxygen in the Air Today?	Answer
27	Give one Use of Nitrogen.	Answer
28	Give one Use of Oxygen.	Answer
29	Give one Use of Argon.	Answer