What percentage of air is nitrogen?

Air is primarily composed of nitrogen, which makes up approximately 78-79% of the Earth's atmosphere by volume. This large percentage indicates that nitrogen is the most abundant gas in the air humans and other animals breathe.

Choosing 79% as the answer aligns with the commonly accepted scientific understanding of atmospheric composition. While the exact percentage can vary slightly depending on altitude and other environmental factors, for practical purposes and standard reference, 79% is the accepted figure for the nitrogen content of air at sea level.

The other figures provided do not accurately reflect the well-established measurement of nitrogen in the atmosphere.