Which process is primarily responsible for the formation of heavier elements in the universe?

• A. Nuclear fusion in the cores of massive stars
• B. Chemical reactions between atoms in interstellar space
• C. Radioactive decay of unstable isotopes
• D. Condensation of gases in planetary atmospheres

Answer: (A)

Verified step by step guidance

1. Understand that the formation of heavier elements in the universe involves nuclear processes occurring in stars, not chemical reactions or physical condensation.
2. Recall that nuclear fusion is the process where lighter atomic nuclei combine to form heavier nuclei, releasing energy in the process.
3. Recognize that in the cores of massive stars, extreme temperature and pressure conditions allow fusion of elements heavier than hydrogen, such as helium, carbon, and beyond.
4. Note that radioactive decay involves the breakdown of unstable isotopes and does not create heavier elements but rather transforms existing ones.
5. Conclude that the primary process responsible for the formation of heavier elements is nuclear fusion occurring in the cores of massive stars.