· The air is a mixture of gases.
· In the atmosphere, there is:
® 78% Nitrogen
® 21% Oxygen
® 0.9% Argon
® 0.03% Carbon Dioxide
® Varied amount of water vapour
The early Earth’s atmosphere:
® Earth was formed about 4.5 billion years ago and its early atmosphere was probably formed from the gases given out by volcanoes.
® There was intense volcanic activity for the first billions years of the Earth’s existence.
® Atmosphere was majority carbon dioxide and no oxygen. There were smaller amounts of water vapour, ammonia and methane.
® As the Earth cooled down, most of the water vapour condensed…