Easy MCQ +4 / -1 PYQ · JEE Mains 2022

In the following nuclear reaction,

$$D\buildrel \alpha \over \longrightarrow {D_1}\buildrel {{\beta ^ - }} \over \longrightarrow {D_2}\buildrel \alpha \over \longrightarrow {D_3}\buildrel \gamma \over \longrightarrow {D_4}$$

Mass number of D is 182 and atomic number is 74. Mass number and atomic number of D4 respectively will be _________.

  1. A 174 and 71 Correct answer
  2. B 174 and 69
  3. C 172 and 69
  4. D 172 and 71

Solution

<p>Equivalent reaction can be written as</p> <p>$D\buildrel {} \over \longrightarrow {D_4} + 2\alpha + {\beta ^ - } + \gamma$</p> <p>$\Rightarrow$ Mass number of D<sub>4</sub> = Mass number of D $-$ 2 $\times$ 4</p> <p>= 182 $-$ 8 = 174</p> <p>$\Rightarrow$ Atomic number of D<sub>4</sub></p> <p>= Atomic number of D $-$ 2 $\times$ 2 + 1</p> <p>= 74 $-$ 4 + 1 = 71</p>

About this question

Subject: Physics · Chapter: Atoms and Nuclei · Topic: Radioactivity

This question is part of PrepWiser's free JEE Main question bank. 184 more solved questions on Atoms and Nuclei are available — start with the harder ones if your accuracy is >70%.

Drill 25 more like these. Every day. Free.

PrepWiser turns these solved questions into a daily practice loop. Chapter-wise drills, full mocks, AI doubt chat. No auto-renew.

Start free →