SOLUTION: Suppose you begin with 2.8 mg of a pure radioactive substance and 3.6 h later determine that 0.35 mg remain. What is the half-life of the substance?
Question 428542: Suppose you begin with 2.8 mg of a pure radioactive substance and 3.6 h later determine that 0.35 mg remain. What is the half-life of the substance? Answer by Gogonati(855) (Show Source):
where M is th actual mass of the substance, Mo is the mass after t= 3.6 h,
and k is decay coefficient. Substitute our values:
, Take ln for both sides.
k=-0.212 Now that, we know the coefficient of half-life, can compute the half-life.
, Take ln for both sides.
h.
