Approximately what percentage of Earth's atmosphere is oxygen?

Understand the Problem

The question asks about the approximate percentage of oxygen in Earth's atmosphere. We need to identify the correct proportion of oxygen relative to other gases in the atmosphere.

More Information

Earth's atmosphere consists of approximately 78% nitrogen, 21% oxygen, 0.93% argon, 0.04% carbon dioxide, and trace amounts of other gases.

Tips

A common mistake is confusing the percentages of nitrogen and oxygen in the atmosphere. Nitrogen is the most abundant gas, making up about 78%, while oxygen is about 21%.

Sources

• The Atmosphere - noaa.gov
• Atmosphere - National Geographic Education - education.nationalgeographic.org
• What percentage of Earth's atmosphere is oxygen? - CK-12 - ck12.org