Question

Give two differences between nuclear fission and nuclear fusion.

Hint:

Think of the words: Fission sounds like "fissure" (a split). Fusion sounds like "fuse" (to join together). This can help you remember the basic definition of each process.

Answer 1

Step 1: Understanding the Concept:
Both are nuclear reactions that release massive amounts of energy by changing the binding energy per nucleon.
Step 2: Detailed Explanation:
Two major differences are:
1. Process: In nuclear fission, a heavy nucleus (like Uranium-235) splits into two or more lighter nuclei. In nuclear fusion, two or more light nuclei (like Hydrogen isotopes) combine to form a heavier nucleus.
2. Control and Conditions: Fission can be controlled in a nuclear reactor using control rods and moderators. Fusion requires extremely high temperatures (approx. \( 10^7\text{ K} \)) to overcome electrostatic repulsion, making it difficult to control for steady power production on Earth currently.
Step 3: Final Answer:
(i) Fission is splitting of heavy nuclei; Fusion is joining of light nuclei.
(ii) Fission produces radioactive waste; Fusion produces mostly non-radioactive waste (like Helium).