Question

Th number of $\alpha and{\beta }^{-}-$ emitted during the radioactive decay chain starting from ${}_{88}^{226}Rs$ and ending at ${}_{82}^{206}Pb$ us

• A. $5\alpha$ and $4\beta$.
• B. $4\alpha$ and $4\beta$.
• C. $5\alpha$ and $5\beta$.
• D. $6\alpha$ and $4\beta$.

Answer 1

Answer: (A)

$5\alpha$ and $4\beta$.

${}_{88}^{226}Ra{\to }_{82}^{206}Pb$

$\begin{array}{c}\text{"A" decreases from}226\text{to}206\\ \text{Difference}226-206=20\\ \text{we know for each}{}^{\prime \prime }{\alpha }^{\prime \prime }\text{particle "A "}\\ \text{decreases by "4"}\\ \therefore \text{No of}\alpha \text{particles emitted is}5\\ \text{After "5"}\alpha ,emissions\end{array}$

${}_{88}^{226}Ra{⟶}_{78}^{206}X{\frac{}{\beta }}_{82}^{206}X$

$x=82-78=4$

$\therefore 4\beta$

$5\alpha$ and $4\beta$.