Question

The half-life of1 is 8.04 days. (a) Calculate the decay constant for this isotope. (b) Find the number of 1311 nuclei necessary to of 0.5 uCi produce a sample with an activity

Answer 1

Step-by-step explanation:

Given that,

`T_{(1)/(2)}=8.04\ days`

We need to calculate the decay constant

Using formula of decay constant

`\lambda=\frac{0.693}{t_{(1)/(2)}}`

`\lambda=(0.693)/(8.04*24*3600)`

`\lambda=9.97*10^(-7)\ sec^(-1)`

We need to calculate the number of
`^(131)I` nuclei

`N=(A\ ci)/(\lambda)`

Where,

A= activity

ci = disintegration

`N=(0.5*10^(-6)*3.7*10^(10))/(9.97*10^(-7))`

`N=1.855*10^(10)`

Hence, This is the required solution.