What is nuclear reaction

In Nuclear physics and nuclear chemistry, a nuclear reaction is semantically considered to be the process in which two nuclei, or a nucleus and an external subatomic particle, collide to produce one or more new nuclides.

Explanation:

Volume of one mole of a gas = 22.4 litre.

No of molecules in one mole of gas = 6.02 x 10²³ .

Volume of one molecule = 4/3 π R³

= 4/3 x 3.14 x ( 167 x 10⁻¹² m )³

= 19.5 x 10⁶ x 10⁻³⁶ m³

=19.5 x 10⁻³⁰ m³

= 19.5 x 10⁻³⁰ x 10³ litre .

=  19.5 x 10⁻²⁷ litre .

So volume occupied by molecules in one mole of gas

= 19.5 x 10⁻²⁷ x 6.02 x 10²³  litre

117.4 x 10⁻⁴ litre

= .01174 litre.

Excluded volume

= ( 22.4 -  .01174  ) litre .

= 22.388 litre.