Question

Which two gases make the bulk of the atmosphere?

Answer 1

Hint: Atmosphere is a mixture of many gases which surround us.Nitrogen and oxygen are the two major constituents of the atmosphere gases.

Complete answer:
Nitrogen (78.084%) and Oxygen (20.947%) are the two major constituents that make up about 99% of the air. Carbon dioxide and argon, along with other inert gases, ozone and water vapour collectively constitute the rest 1% of the atmosphere.

Gases	Percentage of gases by volume in dry air
Nitrogen	78.084
Oxygen	20.947
Argon	0.934
Carbon dioxide	0.038
Other inert gases	0.002
Ozone	Trace to 0.0008

Additional information:
The density of the atmosphere decreases with altitude and 97% of the total mass of the atmosphere is concentrated within the region up to 25 km altitude. Nitrogen and oxygen are the two major constituents that make up about 99% of the air. Oxygen is produced by vegetation and removed by a variety of organic and inorganic processes. It is the most important gas for the survival of living organisms. Nitrogen is relatively chemically inactive and serves as a diluent. It is added to air by decay or burning of organic matters, volcanic eruptions etc, and is removed by certain biological processes. Carbon dioxide and argon, along with other inert gases, ozone and water vapour collectively constitute the rest 1% of the atmosphere.

Note:It is important to mention that the concentration of Nitrogen and Oxygen remains constant up to an altitude of 80 km in our atmosphere. However, concentrations of ozone, carbon dioxide and water vapour are subject to spatio-temporal variations.