Question

A certain radioactive substance has a half life of $30$ days. Find its disintegration constant.

• A. $0.02310$ per day
• B. $0.02310$ per month
• C. $1.0231$ per day
• D. $2.031$ per day

Answer 1

The correct option is A $0.02310$ per day

$\begin{array}{c}\text{Given-}\text{half life}=30\text{days}\left(t_{1/2}\right)\\ \text{we know that, for Half life we have-}\\ \lambda \cdot t_{112}=\ln 2,\lambda =\text{disintegration constant.}\end{array}$

$\begin{array}{c}\Rightarrow \lambda =\frac{\ln 2}{t_{112}}=\frac{\ln 2}{30}\\ \lambda =0.02310\text{per day.}\end{array}$