alleryStart learning →Which gas makes up the largest share of the air at Earth's surface?
AOxygen gas
BNitrogen gas
CArgon gas
DMethane gas
Answer & Solution
Correct answer: B. Nitrogen gas
1. Surface air is a mixture, and two gases dominate it.
2. Nitrogen supplies about 78 percent of the air by itself.
3. Oxygen comes second at about 21 percent, and argon holds about 1 percent.
4. Methane is only a trace gas, far too rare to lead the list.
_Source: OpenStax Astronomy (CC BY 4.0), section 8.3 Earth’s Atmosphere_
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