Answer: Option (#) is the correct answer.
Explanation:
Particles emitted by the given radioisotopes are as follows.
[tex]^{137}_{55}Cs \rightarrow ^{0}_{-1}e + ^{137}_{56}Ba[/tex]
A beta particle is emitted by Cs-137
[tex]^{53}_{26}Fe \rightarrow ^{0}_{+1}e + ^{53}_{25}Mn[/tex]
A positron is emitted by Fe-53.
[tex]^{220}_{87}Fr \rightarrow ^{4}_{2}He + ^{216}_{85}At[/tex]
An alpha particle is emitted by Fr-220
[tex]^{3}_{1}H \rightarrow ^{3}_{2}He^{1+} + e^{-}/tex]
Thus, we can conclude that Fr-220 radioisotope emits particles having the greatest mass.
