I'm having trouble working out how to calculate the number of unstable nuclei remaining in a sample after 28 hours, the answer is 10 but I have no idea how its done, any help would be greatly appreciated.(adsbygoogle = window.adsbygoogle || []).push({});

"If a sample of radioactive material initially has 3.7 x 10(^7) unstable nuclei, how many would remain after 28 hours if the decay constant is 1.5 x 10(^-4)s(^-1)?"

It suggested to use N = N_0 exp (^-decay constant x t) I converted the 28 hours to seconds giving me 100800, but I don't know what the "exp" is for or does.

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# Homework Help: Radioactiviy - # of unstable nuclei after 28 hours

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