Which gas makes up the largest percentage of Earth's atmosphere?
A
Nitrogen
B
Carbon dioxide
C
Oxygen
D
Hydrogen
Correct Answer: Option A — Nitrogen
Explanation:
Nitrogen makes up about 78 percent of Earth's atmosphere, far more than oxygen, which accounts for roughly 21 percent. Nitrogen is largely i...
Nitrogen makes up about 78 percent of Earth's atmosphere, far more than oxygen, which accounts for roughly 21 percent. Nitrogen is largely inert and essential for plant growth, entering ecosystems mainly through nitrogen-fixing bacteria.