What is the composition of the atmosphere in terms of nitrogen and oxygen?

The atmosphere's composition, particularly in terms of nitrogen and oxygen, is well-established, with approximately 78% nitrogen and 21% oxygen making up the majority of the air we breathe. Nitrogen is a largely inert gas that doesn't readily react with other substances under normal conditions, which allows it to be abundant in the atmosphere without contributing significantly to chemical reactions in the environment. Oxygen, while less abundant than nitrogen, is crucial for supporting life as it is essential for respiration in aerobic organisms and is involved in combustion processes.

This understanding of atmospheric composition is fundamental for pilots, as it affects flight dynamics, engine performance, and various other operational considerations in aviation. Recognizing that the atmosphere is primarily nitrogen and oxygen helps in grasping concepts related to altitude effects, weather phenomena, and air density, which are key factors in piloting and flight safety. Thus, the correct composition of approximately 78% nitrogen and 21% oxygen is crucial knowledge for anyone involved in aviation.