Question

They decay constant of radium is $4.28\times {10}^{-4}$ per year. Its half life will be

• A. $2000years$
• B. $1240years$
• C. $63years$
• D. $1620years$

Answer 1

The correct option is D $1620years$

$T=\frac{0.6931\times 1}{\lambda }=\frac{0.6931}{4.28\times {10}^{-4}}year$ $=1620years$