Fission & Fusion

Heavy nuclei split; light nuclei combine.

Concept

Fission & Fusion is a foundational idea in this chapter. The defining relationship is:

$^{235}U + n \to \text{fragments} + \sim200\,\mathrm{MeV}$

Fusion in stars: p-p cycle gives Q ≈ 26.7 MeV.

Worked Application

Apply the formula to a typical problem from your textbook. Identify the knowns, plug into the equation, and check that the units work out. Always sanity-check the magnitude before accepting an answer.

Common Confusions

• Confusing the variables in the formula — re-read the symbol definitions in the chapter.
• Forgetting unit conversions (cm vs m, g vs kg).
• Ignoring sign conventions where direction matters.

Key Takeaways

• Master the formula $^{235}U + n \to \text{fragments} + \sim200\,\mathrm{MeV}$ and one canonical example.
• See the chapter index for full derivations, traps and exam-grade problems.