(Solved): Uranium-lead (U-Pb) dating of geological samples is one of the oldest and most refined radiometric ...

Uranium-lead (U-Pb) dating of geological samples is one of the oldest and most refined radiometric dating methods, able to determine ages of about 1 million years to over \( 4.5 \) billion years with precision in the \( 0.1-1 \% \) range. The \( \mathrm{U}-\mathrm{Pb} \) dating method relies on two separate decay chains, one of which is the uranium series from \( { }^{238} \mathrm{U} \) to \( { }^{206} \mathrm{~Pb} \), with a half-life of \( 4.47 \) billion years. 5 th attempt Feedback See Hint Geologists unearth a sample of zircon that appears to be a closed system. They find \( 0.702 \) microgram of \( { }^{206} \mathrm{~Pb} \) for \( 1.000 \) microgram of \( { }^{238} U \) present. Approximately how old is the sample? yrs