Correct option : (2)
Explanation :
Given, τ1/2 = Half–life = 1 day = 0.693/λ where λ is the disintegration constant.
∴ λ = 0.693 day-1
N, the number of radioactive atoms present at t = t, is given by N = N0 e–0.693×t
At t = t1 = 2.886 days
The number of atom, ΔN , that have disintegrated in time interval (t2 – t1), is