ATMOSPHERE Flashcards
what % of the atmosphere is nitrogen
78%
what % of the atmosphere is oxygen
21%
name some other gases in earth’s atmosphere
carbon dioxide
water vapor
argon
explain the role of volcanoes in the evolution of today’s atmosphere
volcanoes released water vapor as the earth cooled the water vapor condensed to form our oceans
volcanoes also released huge amounts of carbon dioxide
also, release nitrogen which builds up in the atmosphere
also, release small amounts of methane and ammonia
when there was little oxygen and mainly carbon dioxide what planets was the earth’s atmosphere most like
mars
venus
state the difference between the early atmosphere and todays
- there is more nitrogen in today’s atmosphere
- the early atmosphere contained large amounts of carbon dioxide but today there is only a small amount
- the early atmosphere contained very little oxygen but today it makes up 21% of the atmosphere
how did the amount of carbon dioxide in the atmosphere decrease
- the oceans
(some of the carbon dioxide in the atmosphere is dissolved in the oceans to form a weak acid. this reacted with minerals in the sea to form precipitates) - overtime this formed sediments of carbonate rock on the sea bed
- some of the carbon dioxide was used to make corals and shells of organisms (mussels) and when they die they form the SEDIMENTARY ROCK LIMESTONE
- plants take in carbon dioxide during photosynthesis so the carbon is trapped in fossil fuels causing the level of carbon dioxide in the atmosphere to fall
how did the amount of oxygen in the atmosphere increase
- photosynthetic algae
(photosynthesis produced oxygen which entered the atmosphere)
plants evolved