Question

A radioactive element decays at such a rate that after $68$ minutes only one-fourth of its original amount remains. Calculate its decay constant and half-life period.

Answer 1

$Ao=1$ , $t=68$ min

$A=\frac{1}{4}$

$K=?$

$t1/2=?$

$K=\frac{2.303}{60}log\left(4\right)$

$K=0.023{min}^{-1}$

$t1/2=\frac{0.693}{0.023}$

$t1/2=30.130$ min