Scientists thought that cells may have developed the ability to make their own food. As they made their own food, they produced oxygen as a waste product.
The Archean atmosphere is believed to have been free of free oxygen. Banded iron formations did not occur till near the end of the Archean period.
Earths atmosphere dose have oxygen in it, without it we would all be dead we require oxygen to breathe.
oxygen
The Earths atmosphere protects the earth from meteors and it tgives us oxygen
Nitrogen makes up 78% of the earths atmosphere Oxygen makes up 21% of the earths atmosphere
The Archean atmosphere is believed to have been free of free oxygen. Banded iron formations did not occur till near the end of the Archean period.
Earths atmosphere dose have oxygen in it, without it we would all be dead we require oxygen to breathe.
The earths atmosphere is made up of 78% nitrogen and 21% oxygen
no
97%
oxygen
yes
The Earths atmosphere protects the earth from meteors and it tgives us oxygen
Nitrogen makes up 78% of the earths atmosphere Oxygen makes up 21% of the earths atmosphere
Free oxygen
Photosynthesis
oxygen