The half life of a radioisotope is 1.5 hours is (the initial mass of isotope is 32 g)

Options

A. 32 g
B. 16 g
C. 30 g
D. 2 g

Answer

C

Explanation

Mass decayed `=N_(0)=N_(t)` and `N_(t)=(N_(0))/(2^(n))`
`N_(0)=32` and `n=(6)/(1.5)=4`
`therefore N_(t)=(32)/(2^(4))=(32)/(16)=2 g`
`therefore` Mass decayed `=32-2=30` g