Question

The half-life of ${ }_{6} C ^{14}$ (if its $\lambda$ is $\left.2.31 \times 10^{-4}\right)$ is

• A. $ 2\times 10^{2}\,yr $
• B. $ 3\times 10^{3}\,yr $
• C. $ 3.5\times 10^{4}\,yr $
• D. $ 4\times 10^{3}\,yr $

Answer 1

Answer: (B)

The half-life period is the time needed by a radioactive element to decay one half of its original weight.
It is expressed as half-life
$t_{1 / 2} =\frac{0.693}{\lambda} $
$=\frac{0.693}{2.31 \times 10^{-4}} $
$=0.3 \times 10^{4}\, yr$
$=3 \times 10^{3}\, yr$