Half life of Radon Application 86 88 222 Rd is the first decay product of Ra. 222 Radon's activity is much greater than that of its parent. It is the heaviest of all gasses (atomic mass = 222), with a density of almost 10 g /L. Like radium, it is hazardous to handle and should be used with adequate protective shielding. Assume you have an initial sample of radon with a mass of 48 g and that the half-life of radon is four days. Plot the amount of radon left after each four-day time period on graph paper. Questions Determine the answers from the graph and calculate from the half life equation. 1. How many grams of radon would be present after 4 days? 2. How many grams of radon would be present after 12 days? 3. How many grams of radon would be present after 24 days? 4. If 8 g of radon are left, what is the time elapsed? 5. How many grams of radon would be present after 6 days