What is the most abundant element in the air?

The most abundant element in the air is nitrogen, which makes up about 78% of Earth’s atmosphere by volume. This high concentration is significant because nitrogen plays a crucial role in various biological and environmental processes. It is an essential component of amino acids, proteins, and nucleic acids, which are vital for living organisms. Despite being mostly inert in its molecular form (N₂), nitrogen contributes to various ecological balances and cycles in the environment.

Oxygen, while vital for respiration and combustion, constitutes only about 21% of the atmosphere. Carbon dioxide and helium are present in much smaller amounts, with carbon dioxide being approximately 0.04% and helium being trace gases. The dominance of nitrogen in the atmosphere is essential for understanding various agronomic and ecological interactions that shape our environment.