Aspirant Academy
ENHI

RAS question

What is the primary difference between fission and fusion nuclear reactions?

Correct answer: (C) Fission splits heavy nuclei while fusion combines light nuclei, both releasing energy.

Fission splits heavy nuclei into lighter fragments, while fusion combines light nuclei into a heavier nucleus, and both nuclear reactions release energy.

  1. (A)

    Both split heavy atoms

  2. (B)

    Fusion splits atoms while fission combines them

  3. (C)

    Fission splits heavy nuclei while fusion combines light nuclei, both releasing energy

  4. (D)

    There is no difference

Explanation

Fission and fusion differ in the direction of the nuclear change. In fission, a larger atom is forced to split into two smaller atoms, releasing a tremendous amount of energy; uranium and plutonium are typical heavy nuclei used in this process. In fusion, two light atoms come together to form a heavier atom, such as hydrogen atoms fusing to form helium. That is why option C captures the core distinction: fission breaks heavy nuclei apart, while fusion joins light nuclei together. Both are nuclear reactions that release enormous energy, and fusion can release several times more energy than fission.

Why the other options are wrong

  • (A) Both reactions do not split heavy atoms; splitting is the defining feature of fission, while fusion joins light atoms into a heavier atom.
  • (B) This reverses the definitions, because fusion combines light nuclei and fission splits heavy nuclei.
  • (D) There is a clear process difference: fission breaks a larger nucleus apart, whereas fusion forms a heavier nucleus by joining lighter ones.

Concept

This tests the basic Science & Technology concept of nuclear reactions: candidates must distinguish the mechanism of fission from fusion while remembering that both release energy. It recurs in RAS-style questions because a small wording reversal can change the answer completely.

Source

Related questions