The Law of Radioactive Decay (Leaving Cert Physics): Quizzes

Number of nuclei decaying per second

1 disintegration per second

$A = \lambda N$

The radioactive decay constant

$\text{s}^{-1}$

Time for half the nuclei to decay

$T_{1/2} = 0.693/\lambda$

Fast decay with large decay constant

$1/16$

Individual decay is random but large numbers are predictable

Both decrease exponentially

$3 \times 10^8$ nuclei