The Quiz: What is the most common element in Earth’s atmosphere?
Helium
Carbon
Oxygen
Nitrogen
Every time you breathe in air, 78% of that air is nitrogen. Nitrogen is transferred to plants, animals, and the environment through the nitrogen cycle, which is a key part of all life on Earth. Oxygen is the second-most abundant element in the atmosphere, making up 21% of the air. The remaining 1% is mostly argon, with tiny trace amounts of neon, helium, and carbon dioxide.
The correct answer to this quiz is Nitrogen.