Zn (s) -> Zn+2 (aq) + 2e-
Zn (s) with a neutral charge is oxidized and looses two electrons in the process to form ZnCl2 (aq) where Zn has a charge of 2+.
The sum of the percentage abundance of these two isotopes of the new synthetic element should be equal to 100. If we let x be the percent abundance of the second isotope, we have the equation,
62 + x = 100
The value of x from the equation is 38.