If a nucleus such as `.^(226)Ra` that is initially at rest undergoes `alpha`- decay , then which of the following statemnets is true?

Options

A. The alpha particles has more kinetic than the daughter nuclues.
B. The alpha particle has less kinetic energy than the daughter nucleus.
C. The alpha particle and daughter nucleus both have same kinetic energy
D. We cannot say anything about kinetic energy of alpha particle and daughter nucleus.

Answer

a

Explanation

As the alpha particle decays, the daughter nulcues racoils. In such a process,the momentum conservation holds good.
So,
`P_(alpha) =P_(D) =P`
`K_(alpha) =(P^(2))/(2 M_(alpha))` and `K_(D) =(p^(2))/(2 M_(D))`
As `M_(D) gt M_(alpha)`, so `K_(alpha) gt K_(D)`.