The activity of a radioactive sample is the number nuclear disintegrations per second, which is equal to the first-order rate constant times the number of radioactive nuclei present. The fundamental unit of radioactivity is the curie (Ci), where 1 Ci corresponds to exactly 3.701010 disintegrations per second. This decay rate is equivalent to that of 1g of radium 226. The molar mass of Ra226is226.03g/mol. Calculate the rate constant for the radium decay. 10s1 (Enter your answer in scientific notation.) CaIculate the half-life for the radium decay. 10 (Enter your answer in scientific notation.) Starting with 5.0g of the radium sample, what is the activity after 6.0102 yr? Ci