Given that Nitrogen$-16(716$N$)$ has a decay constant $\backslash$lambda $=0\mathrm{.}0972$sec$,$ what fraction of a sample of $716$N will remain after $15$ seconds? e$-\backslash$lambda t$=$e$-0\mathrm{.}097215=0\mathrm{.}233=23\mathrm{.}3\%$ What fraction will have decayed? $1-$e$-\backslash$lambda t$=1-0\mathrm{.}233=76\mathrm{.}7\%$