What is the probability that a radioactive atom having a mean life of 10 days decays during the fifth day?

Answer

C

Explanation

`1/lambda=10 days`
`:.` `lambda=0.1day^-1`
Probability of decay
=Number of atoms decayed/Initial number of atoms
`=(N_0(1-e^(-lambdat)))/(N_0)`
`=1-e^(-lambdat)=1-e^(-0.1xx5)`
`0.39`