Nitrogen and oxygen
It is a byproduct of the life processes on Earth. Earth's early atmosphere contained no Oxygen, but Earth was slowly Terra-formed by life and obtained an Oxygen rich atmosphere.
Alkali earth metals react with oxygen to form basic oxides.
Oxygen, Nitrogen and Carbon dioxide, in that order. The most important element to sustaining life is Oxygen.
You will die
No. Earth's atmosphere most likely originate from volcanic atmosphere. The oxygen is produced by plants.
Nitrogen and oxygen
Earth
Oxygen is main gas of earth. If there is no oxygen in the earth all the life in the earth should die.
There are many places where weather could potentially originate on Earth. Most of the weather on Earth originates from the atmosphere.
From the goddess
earth origin
we get oxygen from the trees
Earth's atmosphere, including the oxygen, is bound to Earth by gravity.
4.6 BYA
mantle
Underground - from radioactive decay.