C9 Summary Notes

Evolution of the atmosphere 1

-Volcanoes give off carbon dioxide, nitrogen, water vapour, methane and ammonia.

- Most of the atmosphere is CO2. There is no oxygen.

Evolution of the atmosphere 2

- water vapor condensed into oceans

- CO2  dissolved into the oceans and precipitated to form sedimentary rocks

- plants and algae evolved and absorbed CO2 for photosynthesis

- when marine animals evolved shells and skeletons that became a store for carbon and turned into fossil fuels

Evolution…