Composition of exhaled air
Breathing is part of the respiratory system, a complex process where air travels into and out of the lungs. The composition of exhaled air (air that is breathed out) is very different from the composition of inhaled air (air that is breathed in). Exhaled air consists of 78 per cent nitrogen, 16 per cent oxygen, 4 per cent carbon dioxide and potentially thousands of other compounds. Inhaled air has the same composition as normal air, it contains 78% nitrogen 21% oxygen 1% inert gas such as argon 0.04% carbon dioxide
- The difference between the amount of oxygen in inhaled and exhaled air is equal to the difference in the amount of carbon dioxide in exhaled and inhaled air.