The atmosphere

At the end of this activity, students should be able to:
– explain how the Earth's atmosphere evolved before reaching its present composition
– describe the approximate percentage composition of the atmosphere at present
– discuss the structure of the atmosphere
– describe the process of formation of radicals by the break-up of a covalent bond
– explain how chlorine radicals can deplete the ozone layer
– explain the effect of the ozone-hole expansion on human health
– explain how the ozone layer is formed
– describe the causes of the greenhouse effect, and what impact it could have on the living conditions on Earth.