A mineral presently retains of its original content

CHEMISTRY · Single correct · US High School · Chemistry · Atomic Structure & Nuclear · Atomic Structure & Nuclear

Problem

A mineral presently retains

60\%

of its original

^{40}\text{K}

content. The half-life of

^{40}\text{K}

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

. The approximate age of the mineral is (a)

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

(b)

5.0\times10^{8}\,\text{years}

(c)

9.2\times10^{8}\,\text{years}

(d)

1.65\times10^{9}\,\text{years}