Answer:
The correct option is a: Hg-183.
Explanation:
The alpha decay is given by:
[tex]^{A}_{Z}X \rightarrow ^{A-4}_{Z-2}Y + ^{4}_{2}He[/tex]
Hence, if Polonium-191 decays by emitting an alpha particle we have:
[tex]^{191}_{84}Po \rightarrow ^{187}_{82}Pb + ^{4}_{2}He[/tex]
Now, if Pb-187 also decays by emitting an alpha particle we have:
[tex]^{187}_{82}Pb \rightarrow ^{183}_{80}Hg + ^{4}_{2}He[/tex]
Therefore, the correct option is a: Hg-183.
I hope it helps you!
