we can calculate the rate of decay by this formula Rate of Decay Formula
The rate of decay for radioactive particles is a first order decay process. This means it follows an exponential decay pattern which can be easily calculated.
Nt = the amount of radioactive particles are time (t)
N0 = the amount of radioactive particles at time = 0
λ = rate of decay constant
t = time
Taking the natural log of both sides of this equation (remember it is an exponential decay) will yield: