If the half-life of a radioactive material is 8 years, how many years will it take for one-half of the original amount of material to decay?

8 years.

Explanation:

Given data:

Half life of radioactive material = 8 years

Time taken to decay half amount = ?

Solution:

If the half life of an radioactive material is 8 years it means half of its amount will decay in 8 years.

Consider that the original amount of material is 100 g.

At time zero = 100 g

At 1st half life = 100 g/2 = 50 g

Number of half life = T elapsed / Half life

         1    =  T elapsed / 8 years

         1 × 8 years = T elapsed

          T elapsed  = 8 years

SO after 8 years its amount would be remain half.