Posted by **RC** on Monday, October 12, 2009 at 12:03pm.

An Initial amount of 100 grams of Thorium-234 decays according to the model: dP/dt=-0.02828P (where t is measured in years).

a) Find the equation for the amount of Thorium left after t years.

b) Determine the half-life of this radioactive isotope

c) How long will it take for the sample to reduce to 25 grams?