Question

A radioactive element has decay constant $6.93\times {10}^{-3}se{c}^{-1}$. Its half-life period in seconds is:

• A. 10
• B. 100
  
• C. 50
• D. 200

Answer 1

The correct option is B 100

A radioactive element has decay constant $6.93\times {10}^{-3}se{c}^{-1}$.

$t_{1/2}=\frac{0.693}{\lambda }$

$=\frac{0.693}{6.93\times {10}^{-3}se{c}^{-1}}$

$=100sec$