Question

The half life period of radioactive substance is 4 days what will be disintegration mass after 2 days

Answer 1

A(sub t) = A(sub 0) x (1 / 2)^(time / half-life), where A(t) = amount remaining at measured timed t, and A(sub 0) is initial amount at time = 0.  

So at t = 2 days, the amount remaining is this:  

A(sub 2 days) = A(sub 0) x (1 / 2)^(2 days / 4 days)  

= A(sub 0) x (1 / 2) ⁽¹ ²⁾ simplifying  

= A(sub 0) * √(1 / 2)  simplifying  

=  70.71% * A(sub 0)  Approximation.  

So nearly 71% of the original mass remains after 2 days of disintegration.