Answer :
It will take 8 years to decay one half of the original amount of the material.
Explanation:
Radioactive materials are those which emit radiations on decaying. So the decay of radioactive materials obey a exponential order.
[tex]N = N_{0}e^{-kt}[/tex]
Here, N is the number of radioactive materials present in time t, N₀ is the amount of radioactive material present at original state or at starting. Also k is termed as the disintegration constant and t is the time taken for decay.
So, disintegration constant is the rate at which the radioactive material will decay. In order to determine the time required to decay half of the original amount of radioactive materials, then we have to perform ratio of ln 2 to disintegration constant. This formula is defined as the half life time of the radioactive materials.
Thus, it can be stated as the time required to decay one half of the original amount of any radioactive material is defined as half life time of that material.
Since, here the radioactive material is said to have a half life time of 8 years, then it will require 8 years to decay one half of the original amount of the material.