What is the most abundant gas in the atmosphere?

The most abundant gas in the Earth's atmosphere is nitrogen. Comprising about 78% of the atmosphere by volume, nitrogen plays a crucial role in various biological and chemical processes. This inert gas is vital for the nitrogen cycle, which is essential for plant growth as it is a key component of amino acids and nucleic acids.

While oxygen is also a significant component of the atmosphere, making up approximately 21%, it is the second most abundant gas. Carbon dioxide, although important for the carbon cycle and climate regulation, constitutes only about 0.04% of the atmosphere. Argon, another trace gas, accounts for about 0.93%. The predominance of nitrogen in the atmosphere signifies its fundamental role in supporting life and influencing various environmental processes.