Nitrogen is the element that makes up most of Earth’s atmosphere, making up about 78% of the air by volume.

Quick Scoop

  • The main component of Earth’s atmosphere is nitrogen gas (N₂), at roughly 78% of dry air by volume.
  • Oxygen (O₂) is second, at about 21%, with argon around 0.9% and carbon dioxide plus other gases making up the remaining fraction.

Why nitrogen dominates

  • Nitrogen is very stable chemically in its N₂ form, so it accumulates and stays in the atmosphere for a long time.
  • Biological and geological processes (like the nitrogen cycle and volcanic outgassing) help keep large amounts of nitrogen in the air over billions of years.

Simple takeaway

  • If someone asks “which element makes up most of the Earth’s atmosphere,” the short, correct answer is: nitrogen.

Information gathered from public forums or data available on the internet and portrayed here.