Question

The particles emitted during the sequential radioactive decay of ${}^{238}{U}_{92}$ to ${}^{206}P{b}_{82}$ are.

• A. $5\alpha$ and $6\beta$
• B. $6\alpha$ and $8\beta$
• C. $8\alpha$ and $4\beta$
• D. $8\alpha$ and $6\beta$

Answer 1

Answer: (D)

$8\alpha$ and $6\beta$

The particle emitted during the sequential radioactive decay of uranium and lead are 8 alpha and 6 beta since in that case atomic and the mass number will be equal to that of the product.

Eight alpha decay corresponds to a decrease in mass number by $4\times 8=32$ and a decrease in atomic number by 16 and 6 beta decay corresponds to an increase in atomic number by 6.