If you can please answer these questions and show work if possible..
Going to be using this as a "Study Guide"

1. Assuming a half-life of 1599 y, how many years will be needed for the decay of 15/16 of a given amount of radium-226?

2. The half-life of radon-222 is 3.824 days. How much time must pass for one-fourth of a given amount of radon to remain?

3. The half-life of polonium-218 is 3.0 min. If you start with 16 mg of polonium-218, how much time must pass for only 1.0 mg to remain?

View the original article here