The atmosphere Flashcards
What percent of the atmosphere is nitrogen
78
What percent of the atmosphere is oxygen
21
What is the small proportion of the atmosphere made up of
other gases e.g. carbon dioxide
How old is the Earth
4.6 billion years old
What activity occurred during the Earth’s early years
Intense volcanic activity
What did the volcanoes release
The gases that formed the atmosphere
What happened as the Earth cooled
The water vapour condensed to form oceans
What gas do volcanoes particularly release
Carbon dioxide
What did the Earth’s atmosphere mainly consist of
Mainly carbon dioxide, with little oxygen
The earth early atmosphere is similar to which planets
Mars and Venus
During the earth’s early atmosphere, what was the carbon dioxide used for
Corals and shells of organisms, and after they died they formed limestone which removed carbon dioxide from the atmosphere
What occurred 2.7 billion years ago
The first photosynthetic algae evolved in the oceans.
What was the impact of photosynthetic algae
They photosynthesized which released oxygen into the atmosphere, over time as plants evolved the amount of oxygen in the atmosphere increased
What are fossil fuels
nonrenewable resource that has formed over millions of years
How is coal formed
from the remains of ferns and trees that die in marshy wetlands because they do not decompose as they have a lack of oxygen, over time the plant remains are covered in sediment and compressed under high pressure and temperature
