Answer:
The answer to your question is below
Explanation:
As Helium is formed, the mass number of Polonium will diminish in 4 units and the atomic number will diminish in 2 units.
All the reactions will form Lead but all are isotopes of this element because they have a different mass number.
a) ²¹⁰₈₄Po ⇒ ⁴₂He + ²⁰⁶₈₂ Pb
b) ²¹⁴₈₄Po ⇒ ⁴₂He + ²¹⁰₈₂ Pb
c) ²¹⁸₈₄ Po ⇒ ⁴₂He + ²¹⁴₈₂ Pb
