Potassium-40 has a half-life of approximately 1.25 billion years. approximately how many years will pass before a sample of potassium-40 contains one-sixteenth the original amount of parent isotope?

It will take 5 billion years for the parent isotope to get reduced to one-sixteenth of its original amount.

Explanation:

Initial amount of an isotope =

Amount left after the radio decay = N=

Decay constant=

Half life of the sample: =1.25 billion years

Years pass before a sample of potassium-40 contains one-sixteenth the original amount of parent isotope be ,t= T

It will take 5 billion years for the parent isotope to get reduced to one-sixteenth of its original amount.