The fundamental unit of radioactivity is the curie (Ci) where 1Ci corresponds to exactly 3.7x10^10 disintegrations per second. The activity of a radioactive sample is the number of nuclear disintegrations per second, which is equal to the first order rate constant times the numbers of radioactive nuclei present. This decay rate is equivalent to that of 1g of radium-226. Determine the rate constant and half life for the radium decay. Starting with 1.0g of the radium sample, what is the activity after 500yr? The molar mass of Ra is 226.03 g/mol