Uranium ores on Earth at present typically consist of and

PHYSICS · Subjective · CBSE · Physics · Nuclei · Nuclei

Problem

Uranium ores on Earth at present typically consist of

99.3\%

{}^{238}_{92}\mathrm{U}

and

0.7\%

{}^{235}_{92}\mathrm{U}

. The half-lives of these isotopes are

4.47\times10^9\ \mathrm{yr}

and

7.04\times10^8\ \mathrm{yr}

, respectively. If these isotopes were equally abundant when Earth formed, estimate the age of Earth.