What is the largest percentage of the air we breathe composed of?

What is the largest percentage of the air we breathe composed of?

• A. Oxygen
• B. Carbon dioxide
• C. Nitrogen
• D. Argon

Answer: (C)

The composition of the air we breathe is primarily made up of nitrogen, which accounts for about 78% of the Earth's atmosphere. This significant proportion makes nitrogen the largest component of the air. While oxygen is the second most abundant gas at about 21%, other gases like carbon dioxide and argon are present in much smaller amounts, with carbon dioxide typically around 0.04% and argon about 0.93%. Understanding this composition is important in fields such as exercise physiology, as it impacts respiration and oxygen delivery during physical activity.

The composition of the air we breathe is primarily made up of nitrogen, which accounts for about 78% of the Earth's atmosphere. This significant proportion makes nitrogen the largest component of the air. While oxygen is the second most abundant gas at about 21%, other gases like carbon dioxide and argon are present in much smaller amounts, with carbon dioxide typically around 0.04% and argon about 0.93%. Understanding this composition is important in fields such as exercise physiology, as it impacts respiration and oxygen delivery during physical activity.