[eli5] If a half-life is the amount of time it takes for a radioactive substance to lose half its radioactivity, and this number is constant no matter how much radiation remains, will there come a time when the substance loses all radioactivity?

Question

[eli5] If a half-life is the amount of time it takes for a radioactive substance to lose half its radioactivity, and this number is constant no matter how much radiation remains, will there come a time when the substance loses all radioactivity?

In: 2

Answer 1

Yes, the substance is made of a finite, albeit large, number of atoms. When you’re down to only one atom, there is a 50% chance it will decay over the next half-life of time. Eventually, however, it decays and you are left with nothing radioactive.