Which is ture about decay constant `(lambda)`?

A radioactive substance (A) is not produced at a constant rate which decays with a decay constant lambda to form stable substance (B).If production of A starts at t=0 . Find (i)The number of nuclei of A and (ii)Number of nuclei at any time t.

(a) Define the terms (i) half-life (T_(1//2) ) and (ii) average life (tau) . Find out their relationships with the decay constant ( lambda) . (b) A radioactive nucleus has a decay constant, lambda = 0.3465 (day) ""^(-1) . How long would it take the nucleus to decay to 75% of its initial amount?

Ac^(227) has a half-life of 22 years . The decays follows two parallel paths What are the decay constant (lambda) for Th and Fr respectively ?

The half-life (T) and the mean-life (barT) are realted to the decay constant (lambda) as

Which is ture about following reactions ?