<u>Answer:</u>
<u>For a:</u> The isotopic symbol of the above atom will be 
<u>For b:</u> The isotopic symbol of the above atom will be 
<u>For c:</u> the isotopic symbol of the above atom will be 
<u>Explanation:</u>
The isotopic representation of an atom is: 
where,
Z = Atomic number of the atom
A = Mass number of the atom
X = Symbol of the atom
Atomic number of iodine = 53
Mass number of iodine = 131
Symbol of iodine = I
The isotopic symbol of the above atom will be 
- <u>For b:</u> Iridium-192
Atomic number of iridium = 77
Mass number of iridium = 192
Symbol of iridium = Ir
The isotopic symbol of the above atom will be 
- <u>For c:</u> Samarium-153
Atomic number of samarium = 62
Mass number of samarium = 153
Symbol of samarium = Sm
The isotopic symbol of the above atom will be 