Which two elements make up the majority of Earth's atmosphere?

• A. Nitrogen and oxygen
• B. Oxygen and carbon dioxide
• C. Nitrogen and hydrogen
• D. Oxygen and argon

Answer: (A)

Verified step by step guidance

1. Recall that Earth's atmosphere is primarily composed of gases, with two elements making up the majority by volume.
2. Understand that nitrogen (N\_2) is the most abundant gas in the atmosphere, making up about 78% of the volume.
3. Recognize that oxygen (O\_2) is the second most abundant gas, constituting about 21% of the atmosphere.
4. Note that other gases like argon, carbon dioxide, and hydrogen are present in much smaller amounts and do not make up the majority.
5. Therefore, the two elements that make up the majority of Earth's atmosphere are nitrogen and oxygen.