Nitrogen gas is most commonly found in which earths sphere?
a. biosphere
b. exosphere
c. atmosphere
d. hydrosphere

Nitrogen is commonly in the form of molecular nitrogen gas (N2) and constitutes about 78% of the air by volume.  The gas is commonly found in the atmosphere. Molecular nitrogen is originally created by fusion processes from carbon and hydrogen in supernovas. Nitrogen is present in small amounts in the hydrosphere. In the biosphere, it is present from air to soil that constitute to the nitrogen cycle.

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