Question

What is the half-life of $\mathrm{Potassium}-40$?

Answer 1

Isotope:

Elements that have the same atomic number but different mass numbers are termed Isotopes.

Potassium here has three isotopes, ${}_{39}\mathrm{K}(93.3\%),{}_{40}\mathrm{K}(0.01\%)\mathrm{and}{}_{41}\mathrm{K}(6.7\%).$

Potassium-40 $\left({}_{40}\mathrm{K}\right)$ which is a radioactive isotope of potassium usually has two half-lives which are mainly based on what type of beta decay that it undergoes.

If Potassium-40 decays through beta emission then its half-life will be $1.28\times 109\mathrm{years}.$

On the other hand, if potassium-40 decays through positron emission the half-life will be $1.19\times 1010\mathrm{years}.$