Radioactive disintegration is a first order reaction and it's rate depends only upon the nature of nucleus and does not depend upon external factors like temoperature an pressure. The rate of radioactive disintigration (Activity) is respresented as `(-d(N))/(dt)=lambdaN`
Where `lambda`=decay consatant, N= number of nuclei at time t, `N""_(0)`=initial no. of nucleei. The above equation after integration can be represented as
`lamda=2.303/tlog.(N""_(0))/(N)`
Half-life period of `U""^(237)` is `2.5xx10""^(5)` years. In how much time will the amount of `U""^(237)` remaining be only 25% of the original amount?

Options

A. `2.5xx10""^(5)` years
B. `1.25xx10""^(5)` years
C. `5xx10""^(5)` years
D. `10""^(6)` years

Answer

c

Explanation

`N=N""_(0)/2""^(n)(n=2)`