this exercise uses the radioactive decay model. after 3 days a sample of radon-222 has decayed to 58% of its original amount. (a) what is the half-life of radon-222? (round your answer to two decimal places.) 4 incorrect: your answer is incorrect. days (b) how long will it take the sample to decay to 30% of its original amount? (round your answer to two decimal places.)
