Curium has a half life of 1.5 hours, how much of a 1000g sample remains after: 1.5 hrs? 3hrs? 4.5 hrs? 6hrs?
Let's assume the radioactive decay of curium follows first-order kinetics.
Let's derive the rate constant,
and rearrange (2),
is how your data would work out.
Note: I used a relatively advanced method to solve this, lots of beginning chemistry students use simple arithmetic,