A free neutron beta-decays to a proton with a half-life of 14 minutes .(a)What is the decay constant ?(b)Find the energy liberated in the process.

Answer

A, B, C, D

Explanation

We know,
Half life period `= 0.6931/lambda`
`[When lambda rarr decay constant]
or, `lambda = 0.6931/(14 xx 60)`
`= 8.25 xx 10 s^(-1)`
[As Half life = 14 min = 14 xx 60 sec.]`
Energy `= [(M_p + M_e)]u`
`= [(M_(n u) - M_(pu))- Me_u]c^2`
`=[0.00189u - 511KeV//c^2]`
`[1293159 eV//c^2 -51,1000eV//c^2]c^2`
`=782159eV = 782KeV`.