Earth's atmosphere is mainly composed of which gases?

• A. Carbon dioxide (CO_2) and methane (CH_4)
• B. Argon (Ar) and neon (Ne)
• C. Hydrogen (H_2) and helium (He)
• D. Nitrogen (N_2) and oxygen (O_2)

Answer: (D)

Verified step by step guidance

1. Understand that Earth's atmosphere is a mixture of different gases, but it is dominated by a few major components.
2. Recall that the two most abundant gases in the atmosphere are nitrogen (N\_2) and oxygen (O\_2), which together make up about 99% of the atmosphere by volume.
3. Recognize that other gases like carbon dioxide (CO\_2), methane (CH\_4), argon (Ar), neon (Ne), hydrogen (H\_2), and helium (He) are present only in trace amounts and do not constitute the main components.
4. Therefore, when asked about the main composition of Earth's atmosphere, focus on nitrogen and oxygen as the primary gases.
5. Summarize that the correct answer is nitrogen (N\_2) and oxygen (O\_2) because they are the predominant gases in Earth's atmosphere.