Question

If the half-life period of a radioactive substance is 0.693 years, what is its decay constant ?

• A. $0.2{year}^{-1}$
• B. $0.1{year}^{-1}$
• C. $0.5{year}^{-1}$
• D. $1{year}^{-1}$

Answer 1

The correct option is D $1{year}^{-1}$

Decay constant $\lambda =\frac{0.693}{t_{1/2}}\lambda =\frac{0.693}{0.693}\therefore \lambda =1{year}^{-1}$