Question

PLEASE HELP ME WITH THIS ONE QUESTION

Answer 1

Answer:

$\lambda=1.39\times 10^{-4}\ s^{-1}$

Explanation:

Given that,

The half-life of Barium-139 is $4.96\times 10^3$

A sample contains $3.21\times 10^{17}$ nuclei.

We need to find the decay constant for this decay. The formula for half life is given by :

$T_{1/2}=\dfrac{0.693}{\lambda}\\\\\lambda=\dfrac{0.693}{T_{1/2}}$

Put all the values,

$\lambda=\dfrac{0.693}{4.96\times 10^3}\\\\=1.39\times 10^{-4}\ s^{-1}$

So, the decay constant is $1.39\times 10^{-4}\ s^{-1}$.