How much nitrogen is typically found in the air we breathe?

The composition of the air we breathe primarily consists of nitrogen, which makes up approximately 78% of the atmosphere. This high concentration is important for several reasons. Nitrogen is an inert gas at room temperature, meaning it does not readily react with other substances found in the air. This characteristic allows it to serve as a stable backdrop for the more reactive gases, such as oxygen, which is present at about 21%.

The presence of nitrogen in the atmosphere plays a crucial role in various natural processes, such as the nitrogen cycle, where it is converted into compounds that can be used by living organisms. While the percentage of nitrogen in the air is consistent, variations can occur in different environments, but the typical value remains around 78%.

The other figures presented in the other options do not accurately reflect the typical nitrogen content in the atmosphere, with values like 21% and 22% being representative of oxygen's presence rather than nitrogen. The 76% figure significantly underestimates the amount of nitrogen found in the air.