Chemistry

Problem

A basalt sample originally contained no

^{40}\text{Ar}

. Laboratory analysis now finds that the number of

^{40}\text{Ar}

atoms trapped in the rock is three times the number of remaining

^{40}\text{K}

atoms. Given the half-life of

^{40}\text{K}

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

, estimate the age of the rock. a)

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

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

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

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