What is the second most abundant gas in Earth's atmosphere?

What is the second most abundant gas in Earth's atmosphere?

• A. Oxygen
• B. Nitrogen
• C. Argon
• D. Carbon Dioxide

Answer: (B)

The air we breathe is dominated by two gases in order: nitrogen is the most abundant, and oxygen is the second most abundant. In numbers, nitrogen makes up about 78% of Earth's atmosphere, while oxygen makes up roughly 21%. The remaining tiny fractions come from argon, carbon dioxide, neon, helium, and others, with argon around 0.93% and carbon dioxide about 0.04%. So the second most abundant gas is oxygen, because after the vast majority of nitrogen, oxygen is the next most plentiful component. The other options are present in much smaller amounts and do not approach the proportions of nitrogen or oxygen.

The air we breathe is dominated by two gases in order: nitrogen is the most abundant, and oxygen is the second most abundant. In numbers, nitrogen makes up about 78% of Earth's atmosphere, while oxygen makes up roughly 21%. The remaining tiny fractions come from argon, carbon dioxide, neon, helium, and others, with argon around 0.93% and carbon dioxide about 0.04%.

So the second most abundant gas is oxygen, because after the vast majority of nitrogen, oxygen is the next most plentiful component. The other options are present in much smaller amounts and do not approach the proportions of nitrogen or oxygen.