Question

Find the amount of heat generated by `1.00 mg` of a `Po^(210)` preparation during the mean lifetime period of these nuclei of the emitted alpha-particles are known to possess the kinetic energy `5.3MeV` and practically all daughter nuclei are formed directly in the ground state.

Answer 1

The numbger of nuclei initially present is
`(10^(-3))/(210)xx6.023xx10^(23)= 2.87xx10^(18)`
In the mean life of these nuclei the number decaying is the fraction `1-(1)/(e )= 0.632` . Thus the energy realsed is
`2.87xx10^(18)xx0.632xx5.3xx1.602xx10^(-13)J = 1.54MJ`