Stars are made up mostly of which two elements?

• A. Carbon and oxygen
• B. Nitrogen and neon
• C. Hydrogen and helium
• D. Iron and silicon

Answer: (C)

Verified step by step guidance

1. Understand that stars primarily consist of the simplest and most abundant elements in the universe.
2. Recall that during the formation of stars, hydrogen atoms undergo nuclear fusion to form helium, releasing energy.
3. Recognize that hydrogen and helium together make up the vast majority of a star's mass.
4. Note that heavier elements like carbon, oxygen, nitrogen, neon, iron, and silicon are present in much smaller amounts in stars.
5. Conclude that the two elements stars are made up mostly of are hydrogen and helium.