Radon-222 has a half-life of 3.8 days. A sealed sample of this gas is kept in the laboratory.
a. (a) Calculate its decay constant in s−1. (Take 1day=24h.)
b. (b) Determine the mean life of Radon-222 in seconds.
c. (c) After 11.4days, what percentage of the original nuclei remains undecayed? Also state the percentage that has decayed in this interval.