Question

Part 1-The Half-Life of radon-222 is 3.8 days. How much of a 100-gram sample is left after 30 days?Part 2- Carbon-14 has a Half-life of 10 years, if the sample contained 70mg originally, how much is left after 18 years

Answer 1

In Chemistry, half-life is a way of calculating based on experimental information, how many days will half of the mass or concentration of a certain compound will decay from its initial value.

In our case we have Radon-222, which has a half life of 3.8 days and initial mass of 100 grams, let's see how much of mass Radon-222 will have after 30 days

0 - 3.8 days = 50g

3.8 - 7.6 days = 25 g

7.6 - 11.4 days = 12.5 g

11.4 - 15.2 days = 6.25 g

15.2 - 19 days = 3.125 g

19 - 22.8 = 1.56 g

22.8 - 26.6 = 0.78 g

26.6 - 30.4 = 0.39 g

Therefore after 30 days, we will have 0.39 grams of Radon-222