1. C13.3 Evolution of our Atmosphere

2. Learning Objectives:
Aiming for 4: State that the levels of carbon dioxide have decreased in the atmosphere.
Aiming for 6: Use word equations to show how carbon dioxide can form sedimentary rocks.
Aiming for 8: Use balanced symbol equations to explain how carbon dioxide forms sedimentary rock and how methane and ammonia were removed from the atmosphere.

3. Practical: Testing for carbonates
Safety:
Limewater: IRRITANT
Hydrochloric acid: IRRITANT
Eye protection should be worn throughout the experiment
Hands should be washed at end of experiment

4. Practical: Testing for carbonates

5. Questions Questions about the practical:
Challenge:
Describe how sedimentary rocks formed and locked up carbon dioxide. 
Questions
Questions about the practical:
Aiming for 4: Answer 2 questions
Aiming for 6: Answer 3 questions
Aiming for 8: Answer 4 questions
Questions which apply their knowledge:
Aiming for 4: Start on question 1
Aiming for 6: Start on question 1.d
Aiming for 8: Start on question 2