Question

Consider the nuclear equation below.

What is X?

235/96 Cm
243/92 U
235/92 U
243/96 Cm

Answer 1

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

Answer 2

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
`X_(92)^(235)`.

The correct option is C.