Question

1/4th of a radioactive element is left after two hours.The half life period of the element is

Answer 1

t=(1/k)*ln(a/a-x)

Here, given that, a-x=a/4, after 2 hours,

We have to find out k,

k=0.693 hour^-1

t(1/2)=.693/k

=1 hour