What type of reaction is represented by the following scheme? $_{1} ^{2} X$ + $_{1} ^{2} Y$  -----> $_{2} ^{3} Z$ + $_{0} ^{1} n$ + energy

Analysis of the Question

The equation provided is: $_{1} ^{2} X$ + $_{1} ^{2} Y$ $\rightarrow$ $_{2} ^{3} Z$ + $_{0} ^{1} n$ + energy

We need to identify the type of nuclear reaction occurring here by examining the reactants and the products.

Concept Explanation

• Nuclear Fusion: This is a reaction where two light atomic nuclei (usually isotopes of hydrogen, like deuterium or tritium) combine to form a heavier nucleus, releasing a significant amount of energy in the process.
• Nuclear Fission: This is the opposite of fusion. It occurs when a heavy, unstable nucleus (like Uranium-235) splits into two or more smaller, lighter nuclei, usually triggered by a neutron.
• Chain Reaction: This is a series of fission reactions where the neutrons released from one fission event trigger further fission events.
• Radioactive Decay: This is the spontaneous process by which an unstable nucleus loses energy by emitting radiation (alpha, beta, or gamma particles).

Step-by-Step Solution

1. Examine the reactants: We have two light nuclei, $_{1} ^{2} X$ and $_{1} ^{2} Y$ (both are isotopes of hydrogen, specifically deuterium).
2. Examine the products: These two light nuclei combine to form a heavier nucleus, $_{2} ^{3} Z$ (Helium-3), along with a neutron ($_{0} ^{1} n$) and energy.
3. Compare with definitions: Since two light nuclei are merging to form a heavier nucleus, this is a classic example of nuclear fusion.
4. Check the balance: • Mass numbers: $2 + 2 = 3 + 1$ (Total = 4 on both sides). • Atomic numbers: $1 + 1 = 2 + 0$ (Total = 2 on both sides). • The equation is balanced, confirming it is a valid nuclear reaction.

Conclusion

Because the reaction involves the joining of two light nuclei to form a heavier one, it is classified as a fusion reaction.

Exam Tip

A simple way to remember the difference:

• Fusion = Fusing together (like two small things becoming one big thing).
• Fission = Fission/Fissure (like a crack or split, where one big thing breaks into smaller things).