The activity of a sample of Ti(Z=22) decreased by 90% over a period of 10 years . The half life of the sample is

Options

A. 1 year
B. 2 years
C. 3 years
D. 5 years

Answer

C

Explanation

`t=10 yr, N_(0)=100, N=10`
Putting in the equation
`lambda=(2.303)/(t)"log"(N_(0))/(N)`
`lambda=(2.303)/(10) "log"10=0.2303 Yr^(-1)`
`t_(1//2)=(0.693)/(lambda)=(0.693)/(0.2303)Yr`