7. A 100 mg sample of polonium decays with a half-life of 3.8 days [A7]. a. Write a function for this situation in terms of its half life [1] b. How much radon will remain after i) 1 day ii) 1 week? [2] c. How long will it take for the sample to decay 25% of its mass ?[2] d. What is the rate of decay for each of these times from b) [3] e. What is the disintegration constant [1]