1. C13.1 The History of Our Atmosphere

2. Learning Objectives:
Aiming for 4: Describe how oxygen was formed in the development of the atmosphere. 
Aiming for 6: Explain how oxygen was formed in the development of the atmosphere making reference to the practical.
Aiming for 8: Analyse practical results and suggest how they support your understanding of the development of the atmosphere.

3. Video Clip - Early Atmosphere
Watch the introduction to the Earth's atmoshphere. Make notes on the key stages in the evolution of the atmosphere. What key chemicals are found in the atmosphere?

4. Practical Safety: limewater: IRRITANT
eye protection should be worn throughout the experiment
hands should be washed at end of experiment

5. Questions Questions about the practical:
Aiming for 4: Answer 3 questions
Aiming for 6: Answer 4 questions
Aiming for 8: Answer 5 questions
Students answer all the questions asking them to apply their learnt knowledge.