Radon-222 has a half-life of 3.8 days

CHEMISTRY · Multi-part · US High School · Chemistry · Atomic Structure & Nuclear · Atomic Structure & Nuclear

Problem

Radon-222 has a half-life of 3.8 days. A sealed sample of this gas is kept in the laboratory. (a) Calculate its decay constant in

\text{s}^{-1}

. (Take

1\,\text{day}=24\,\text{h}

.) (b) Determine the mean life of Radon-222 in seconds. (c) After

11.4\,\text{days}

, what percentage of the original nuclei remains undecayed? Also state the percentage that has decayed in this interval.