## Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)

The probability that an excited atom will emit a photon is $~~0.02$
Let $P$ be the probability that an excited atom will emit a photon. We can find $P$: $P = \lambda~\Delta t$ $P = (\frac{1}{\tau})~(\Delta t)$ $P = \frac{\Delta t}{\tau}$ $P = \frac{0.50~ns}{25~ns}$ $P = 0.02$ The probability that an excited atom will emit a photon is $~~0.02$