Define decay constant

A radioactive nuclide can decay simultaneously by two different processes which have decay constants lambda_(1) and lambda_(2) . The effective decay constant of the nuclides is lambda .

A radioactive nuclide can decay simultaneously by two different processes which have decay constant lambda_(1) and lambda_(2) . The effective decay constant of the nucleide is lambda

The activity of a radioactive elements (decay constant lambda ) becomes (1)/(3) of initial activity A_(0) in 9 years then the decay constant after 9 years will :