The earth’s atmosphere

4.6 billion years ago

How long ago was the earth formed

• volcanoes released gases ( carbon dioxide, nitrogen and water vapor) into the atmosphere

• but as the earth began to stabilize the atmosphere was mainly carbon dioxide. There could have been some ammonia, methane, water vapor and nitrogen and very little oxygen

Explain how the earth is early atmosphere was and how that was brought about

• water vapor condenses as the earth gradually cools down and falls as rain. Water collected in Hollows in the crust as the rock solidified and the first ocean was formed.

• Icy comets rained down on the earth and melted

How were water sourced( from water vapor and one other)

Venus and mats because they had mainly carbon dioxide with little or no oxygen

What planets did the early atmosphere of earth resemble and what gases were involved

• Algae was the first plant to be evolved and they produced oxygen as a waste product by photosynthesis and overtime more and more plants evolved which made it possible for the first animal forms to evolve

how was oxygen produced in the atmosphere

Earliest living microorganisms could not tolerate high oxygen concentration because they had evolved without it making them die out

Negative impact of the increase in oxygen

6CO2+ 6H2O = C6 H12 O6 + 6O2

Equation for photosynthesis

Carbon dioxide and water is converted to glucose and oxygen; the carbon in the glucose goes to new plants and animals eat those plants, some of the carbon is transferred to the tissues including skeleton and shells

Explain how humans skeletons and shells are formed

The animal tissues which are skeletons and shells build up at the bottom of the ocean and buried by layers of sediments, the pressure causes deposits to form as sedimentary carbonate rocks like limestone( which are mainly CaCO3)

How is limestone formed

• fossil fuel coal: they are sedimentary rocks that’s formed from the deposit of plant materials and when they die in swamps they are buried in the presence of no oxygen and compressed over years

• Crude oil and common gas: formed from the remains of plankton deposited in the mud on the seabed. They are covered by sediments that became layers of rocks when compressed over years.

What does the remains of heated living things form when heated within the earth’s crust for a long time

• They are melted into the ocean when oceans are formed. The carbonates were precipitated forming sediments

• Plants and algae absorbs carbon dioxide through photosynthesis

• Dead organisms forms fossil fuels which locked up the carbon

• Animals fed on plants which transferred transfers carbons to their tissues, when this organisms die their remains forms sedimentary rocks

How are carbon dioxide removed from the atmosphere

For 200million years

How long has the atmosphere of today been the same

• nitrogen : four fifths( 80percent)

• oxygen: one fifth (20percent)

• Water vapour

• Carbon dioxide

• Noble gases

Whats the atmosphere of today like

• plants that evolves

• Dissolving in oceans

• Formation of sedimentary rocks and fossil fuels that contains carbon

How was carbon dioxide decreased from the atmosphere

Animals fed on plants which has absorbed CO2 and that transferred to their tissues including bones and shells so when they died

They formed sedimentary rocks. Dead organisms turns into fossil fuels

Describe the formation of fossil fuels