After plants developed chlorophyll and multiplied to the point where they could "pollute" the primal atmosphere, somewhere between 1 and 2 billion years ago.
78% nitrogen and 21% oxygen and other gasses make up the last 1% Earth science
The Earth's atmosphere contains primarily nitrogen (about 78%), oxygen (about 21%), and trace amounts of other gases like argon, carbon dioxide, and water vapor. It also contains aerosols, such as dust and pollutants.
Most of Earth's atmosphere is composed of nitrogen, making up about 78% of the air we breathe. Oxygen makes up about 21% of the atmosphere, with trace amounts of other gases like argon, carbon dioxide, and water vapor making up the rest.
The early Earth's atmosphere consisted mainly of carbon dioxide, water vapor, nitrogen, and small amounts of methane and ammonia. Over time, as photosynthetic organisms evolved and produced oxygen, the atmosphere gradually transitioned to contain more oxygen and less carbon dioxide.
The earth's atmosphere is composed as follows:nitrogen: 78%oxygen: 21%argon: 0.9%trace gases make up the remaining less than 0.1% - these include carbon dioxide, neon, helium, methane, krypton, and hydrogen, and the barest amounts of many others
nitrogen,oxygen,carbon dioxide,argon, and other gases in small amounts
It is believed that the early Earth's atmosphere did not contain significant amounts of oxygen. Oxygen began to accumulate in the atmosphere around 2.4 billion years ago due to the emergence of photosynthetic organisms.
The earths atmosphere is made up of 78% nitrogen and 21% oxygen
97%
no
Atmosphere contains roughly (by volume) 78.09% nitrogen, 20.95%oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases.
78% of the Earth's atmosphere is Nitrogen. Another 21% is oxygen, and the final 1% are other gases found is small amounts such as carbon dioxide, helium and methane.
78% nitrogen and 21% oxygen and other gasses make up the last 1% Earth science
Free oxygen
Oxygen gas
Plants
oxygen