What are the chief components of air?

The chief components of air are primarily oxygen and nitrogen, which together constitute about 99% of the Earth's atmosphere. Nitrogen makes up approximately 78% of the air we breathe, while oxygen accounts for around 21%. This composition plays a crucial role in supporting life on Earth, as oxygen is essential for respiration in most living organisms.

Understanding this composition is important in various fields, including environmental science and health, as it relates to air quality and the physiological effects of different gases. The presence of trace gases, such as carbon dioxide and argon, is significant but they comprise a much smaller proportion compared to oxygen and nitrogen. In the context of air quality, pollutants like sulfur dioxide and ozone, while important to monitor, are not chief components but rather result from various industrial and natural processes.