JEE Main 2024 · 8 April · evening · Single correct · +4 / −1
In a hypothetical fission reaction
₉₂ X²³⁶ → ₅₆ Y¹⁴¹+ ₃₆ Z⁹²+3 R
The identity of emitted particles (R) is :
- (a) Proton
- (b) Neutron
- (c) Electron
- (d) γ-radiations
Answer and solution
Answer (b) Neutron
Solution
Physics sir · 3 steps
Balance the charge numbers and the mass numbers separately, and R tells you who it is.
- Two conservation laws. In any nuclear reaction the total charge number (bottom) and the total mass number (top) are the same on both sides. Let each R have charge number Z and mass number A.
92 = 56 + 36 + 3Z 236 = 141 + 92 + 3A
- Solve both. Charge: 56 + 36 = 92, so 3Z = 0 and Z = 0. Mass: 141 + 92 = 233, so 3A = 3 and A = 1.
- So. A particle with no charge and mass number 1 is the neutron, ₀ n¹. The answer is (b).
The idea to keep. For any unknown particle in a nuclear equation, balance the bottom numbers and the top numbers separately. The pair (Z, A) names the particle at once.
Answer from the NTA final answer key. Solution by PrepWiser.