Question

You received a shipment 20 days ago of 13 I for treatment of hyperthyroidism. What fraction of the original shipment would you still have with a half-life of 8.040 days for 31?

Answer 1

we will have 17.8 % of the original value

Step-by-step explanation:

As we know that by radioactive decay the total number of nuclei present at any instant of time is given as

`N = N_o e^(-\lambda t)`

here we need to find the fraction of total number of nuclei present

so we will have

`(N)/(N_o) = e^(-\lambda t)`

so we have

`\lambda = (ln 2)/(8.040)`

now we have

`(N)/(N_o) = e^{-(ln 2)/(8.040)(20)}`

`(N)/(N_o) = 0.178`

so we will have 17.8 % of the original value