A radioactive element `ThA( ._(84)Po^(216))` can undergo `alpha` and `beta` are type of disintegrations with half-lives, `T_1` and `T_2` respectively. Then the half-life of ThA is

Options

A. `T_(1)+T_(2)`
B. `T_(1)T_(2)`
C. `T_(1)-T_(2)`
D. `(T_(1)T_(2))/(T_(1)+T_(2))`

Answer

D

Explanation

`i=I_(1)+I_(2)`
`(ln2)/T=(ln2)/(T_(1))+(ln2)/(T_(2))rArr T=(T_(1))/(T_(1))+(T_(2))/(T_(2))`