Question

An accident in a laboratory results in a room being contaminated by a radioisotope with a half-life of 2 days. If the radiation is measured to be eight times the maximum permissible level, how much time must elapse before the room is safe to enter?

Answer 1

6 days

Step-by-step explanation:

We are given that

Half life,
`t=2 days`

We have to find the time must elapse before the room is safe to enter.

Let maximum permissible level=
`N_0`

Radiation,
`N=8N_0`

Let n be the number of half cycle

`(N)/(N_0)=2^n`

`(8N_0)/(N_0)=2^n`

`8=2^n`

`2^3=2^n`

`n=3`

Time must elapse before the room is safe to enter=
`3t=3* 2=6days`