Question

A nucleus of Radium (²²⁶Ra₈₈) decays to Radon (²²²Rn₈₆) by the emission of an α-particle of energy 4.8 MeV. Calculate the recoil energy of the daughter nucleus.

M(α) = 4.003 μ and M(Rn) = 222 μ

Answer 1

The nuclear reaction involved in the process will be as under

We know that the K.E. of a particle is expressed as:

Because momentum is always conserved (in the absence of external force), hence,