A mineral sample originally contained a certain amount of (half-life )

CHEMISTRY · Subjective · US High School · Chemistry · Atomic Structure & Nuclear · Atomic Structure & Nuclear

Problem

A mineral sample originally contained a certain amount of

^{40}\text{K}

(half-life

1.25\times10^{9}\,\text{yr}

). Today only

20\%

of the original

^{40}\text{K}

atoms remain undecayed. Determine the age of the mineral.