For the nuclear reactions. (A) ₄⁸Be → 2 ₂⁴He (B) ₃₆⁸⁰Kr → 2 ₁₈⁴⁰Ar (Given masses: ⁸Be = 8.005300, ⁴He =… · ABC26IN1340

Subject: Inorganic Chemistry · Chapter: Nuclear Chemistry · Topic: Nuclear Reactions Q Value · Exam: CSIR NET DEC 2011 · Marks: 2 · Difficulty: Easy

For the nuclear reactions.
\[ \text{(A)}\quad {}_4^8\mathrm{Be} \rightarrow 2\,{}_2^4\mathrm{He} \]
\[ \text{(B)}\quad {}_{36}^{80}\mathrm{Kr} \rightarrow 2\,{}_{18}^{40}\mathrm{Ar} \]
(Given masses: $^8\mathrm{Be} = 8.005300$, $^4\mathrm{He} = 4.002603$ and ${}_{36}^{80}\mathrm{Kr} = 79.81638$, ${}_{18}^{40}\mathrm{Ar} = 39.96238$) The correct statement is:
(a)(A) and (B) are both spontaneous fission processes.
(b)(A) is spontaneous fission but (B) is not.
(c)(B) is spontaneous fission but (A) is not
(d)Both (A) and (B) are not spontaneous fission processes.
Answer
Answer: D ✓ checked by 4AB · confidence high

The source book printed B; on checking, D is correct — see the explanation.

Explanation
⁸Be (8.005300) is heavier than 2 × ⁴He (8.005206), so it splits spontaneously; ⁸⁰Kr (79.81638) is lighter than 2 × ⁴⁰Ar (79.92476), so that fission is impossible. (A) spontaneous, (B) not.

Study loop for Nuclear Chemistry

1. Practise the PYQsPrevious-year questions, with answers

· Browse this chapter in the app