Which chemical element is the primary constituent of a young star?

• A. Carbon
• B. Hydrogen
• C. Helium
• D. Oxygen

Answer: (B)

Verified step by step guidance

1. Understand that a young star primarily consists of the simplest and most abundant element in the universe, which is hydrogen.
2. Recall that stars form from clouds of gas and dust, mostly composed of hydrogen atoms, which undergo nuclear fusion in the star's core.
3. Recognize that during the early stages of a star's life, hydrogen nuclei fuse to form helium, releasing energy that powers the star.
4. Note that while elements like carbon, oxygen, and helium are present, they are not the main constituents of a young star.
5. Conclude that hydrogen is the primary chemical element in a young star due to its abundance and role in stellar formation and fusion.