Question

The disintegration constant of radium with half-life 1600 yr is :

• A. $2.12\times {10}^{-4}y{r}^{-1}$
• B. $4.33\times {10}^{-4}y{r}^{-1}$
• C. $3.26\times {10}^{-4}y{r}^{-1}$
• D. none of these

Answer 1

Answer: (B)

$4.33\times {10}^{-4}y{r}^{-1}$

$\lambda =\frac{0.693}{t_1/2}$
where $\lambda =$ disintegration constant = ?
$t_{1/2}=$ 1600 yr
$\therefore \lambda =\frac{0.693}{1600}=4.33\times {10}^{-4}y{r}^{-1}$