Question

Most abundant constituent of dry air in terms of volume is:

• A. carbon dioxide
• B. helium
• C. nitrogen
• D. oxygen

Answer 1

The correct option is C nitrogen

The most abundant gas in the Earth's atmosphere is nitrogen, which accounts for about 78% of the mass of dry air.

Oxygen is the next most abundant gas, present at levels of 20 to 21%.

Although humid air seems like it contains a lot of water, the maximum amount of water vapour that air can hold is only about 4%.

Hence, the correct option is $\text{C}$