Radioactivity

Alpha decay :    

Beta decay  :     

Gamma decay  :    Photons of electromagnetic         radiation emitted from excited nuclei are called gamma rays.

A = activity = l N

Decay law  :  rate of disintegration =

N = N_o e^{-l t} ;      A = A_o e^{- l t}

Ln N = - l t + ln N_o ;    ln N = 2.3 log N  where  ln N = log_e N and log N = log₁₀ N

Plot ln N against t, a straight line is obtained.