What is the composition of air in terms of oxygen, nitrogen, and trace gases?

The composition of air is most accurately represented as approximately 20.95% oxygen, 78.1% nitrogen, and about 1% trace gases. This composition is essential for various biological processes, including respiration in humans and other animals, as well as combustion.

The slight variations in the percentage of oxygen and nitrogen can depend on geographical and environmental factors, but the standard atmospheric composition is widely recognized as close to these values. Oxygen is vital for aerobic life, while nitrogen acts primarily as an inert filler in the atmosphere. The trace gases include argon, carbon dioxide, and others, playing crucial roles in ecological and climatic processes.

Understanding the accurate composition of air is critical in medical settings, particularly regarding respiratory therapies and the storage of medical gases.