A radio nuclide `A_(1)` with decay constant `lambda_(1)` transforms into a radio nuclide `A_2` with decay constant `lambda_(2)`. Assuming that at the initial moment, the preparation contained only the radio nuclide `A_(1)`
(a) Find the equation decribing accumulation of radio nuclide `A_(2)` with time. (b) Find the time interval after which the activity of radio nuclide `A_(2)` reaches its maximum value.

Options

A. `(ln(lambda_(2)//lambda_(1)))/(lambda_(2)-lambda_(1))`
B. `(ln(lambda_(1)//lambda_(2)))/(lambda_(1)-lambda_(2))`
C. `ln(lambda_(2)-lambda_(1))`
D. none of these

Explanation

Conserve the number of nucleons.