Question

If the decay constant of a radioactive nuclide is $6.93$ x $10$${}^{-3}$sec${}^{-1}$, its half life in minutes is:

• A. $100$
• B. $1.67$
• C. $6.93$
• D. $50$

Answer 1

The correct option is B $1.67$

$\lambda =6.93\times {10}^{-3}{sec}^{-1}$
$t_{1/2}=\frac{.693}{.693\times {10}^{-2}}sec$ $=\frac{100}{60}min$ $=1.67min$