The amount of heat generated by `1.0 mg` of a `Po^(210)` preparation during the one mean lifetime period of there nuclei, if the emitted a-particles are known to possess the kinetic energy `5.3 MeV` is `n(0.2 MJ)`. Assume all daughter nuclei are partically formed in ground state. What is the value of `n` ?

Explanation

Number of nuclei initially present `=(10^(-3))/(210)xx6.023xx10^(23)=2.88xx10^(18)`
The no. of decay in one mean lifetime
`=(1-(1)/(e))xx2.88xx10^(18)`
Energy released `= 2.88xx10^(18)xx(1-(1)/(e))xx5.3xx1.6xx10^(-13)J`