Answer: The isotopic symbol that is used to balance the fission reaction is [tex]_{36}^{94}\textrm{Kr}[/tex]
Explanation:
In a nuclear reaction, the total mass and total atomic number remains the same.
For the given fission reaction:
[tex]^{235}_{92}\textrm{U}+_0^1\textrm{n}\rightarrow ^A_Z\textrm{X}+^{139}_{56}\textrm{Ba}+3^1_0\textrm{n}[/tex]
Total mass on reactant side = total mass on product side
235 + 1 = A + 139 + 3
A = 94
Total atomic number on reactant side = total atomic number on product side
92 + 0 = Z + 56 + 0
Z = 36
Hence, the isotopic symbol that is used to balance the fission reaction is [tex]_{36}^{94}\textrm{Kr}[/tex]
