The Atmosphere

Page 1

Unit 1- Composition & Structure

3.4 to 4 billion years ago atmosphere formed when gases fist released because of intense melting of earth's interior

volcanoes release these gases

indication of compisition 4 billion years ago

lots of N

some CO2

little O

people could not have survived

as levels of oxygen increased so living organisms inceased

most oxygen today released by photosynthesis

oxygen made when water broken down into into hydrogen and oxygen during radiation from sun

atmosphere has changed over the years

majority of CO2 dissolved into ocenas and trapped in rocks

sunlighst and oxxygen cuased living organisms that the breaking down of amonia into nitrogen

over last 5 million years begun to stabalize with huge increase in nitogen

gasses held in place by earths gravitational force

Physical properties of the atmosphere

desity of air greater closer to the surface of the earth

air pressure is exerted in all directions