Question

When ${}_{92}{U}^{237}$ nucleus is converted into ${}_{83}B{i}^{209},x$ and $y$ are the number of $\alpha$ and $\beta$ particles emitted respectively then the value of $x$ and $y$, are respectively

• A. $5,7$
• B. $7,6$
• C. $7,5$
• D. $6,7$

Answer 1

The correct option is C $7,5$

For every $\alpha -$ decay, $A$ decreases by $4$ and $Z$ decreases by $2$ and for every $\beta$ decay $Z$ increases by $1$ and $A$ remains the same.
Therefore, if $x$ and $y$ are the number of $\alpha$ and $\beta$ decays,
$237-209=x\left(4\right)\Rightarrow x=7$
$92-83=2x-y$
$\Rightarrow y=5$