Question

the equation $_1^2h + _1^3h \
ightarrow _2^4he + energy$ is an example of
1 alpha decay
2 positron capture
3 fusion
4 fission

Explanation:

1. Analyze each option:

• Alpha decay: Involves emission of an alpha particle (⁴₂He), but here two H atoms combine, not decay.
• Positron capture: A nucleus captures a positron, not relevant here as two nuclei combine.
• Fusion: Process where two light nuclei combine to form a heavier nucleus, releasing energy. Here, two hydrogen (¹₁H) nuclei combine to form helium (⁴₂He) with energy release, matching fusion.
• Fission: Splitting of a heavy nucleus into lighter ones, opposite of what's happening here.

Answer:

1. fusion