To balance the nuclear reaction following rules are following:
1. The sum of the subscript means the atomic numbers must be equal on the both side of the equation.
2. The sum of the superscript means the mass numbers must be equal on the both side of the equation.
94 Pu 239 ------> x+ 2He4
The mass number:
239 = A+4
A= 235
The atomic number:
94 = Z+2
Z= 92
Thus the balanced nuclear reaction is as follows:
94 Pu 239 ------> 92U235+ 2He4
Explanation :
In this decay, Plutonium (Pu) is decayed into X and a helium nuclei. This shows an alpha decay.
In an alpha decay, atomic mass is reduced by four and atomic number is reduced by 2.
So, atomic mass of X is 239 - 4 = 235
and atomic number of X is 94 - 2 = 92
Hence, X is [tex]X_{92}^{235}[/tex].
The correct option is C.
