Problem

### Match the Columns At

t = 0

x

nuclei of a radioactive substance emit

y

nuclei per second. Match the following two columns.

Column I	Column II
(a) Decay constant $\lambda$	(p) $(\ln 2) (x/y)$
(b) Half-life	(q) $x/y$
(c) Activity after time $t = \frac{1}{\lambda}$	(r) $y/e$
(d) Number of nuclei after time $t = \frac{1}{\lambda}$	(s) None of these