Chapter 19, Problem 19.94SP

Interpretation Introduction

Interpretation:

The decay equation can therefore be written:

  $N_t=N_o{e}^{-\lambda t}$

Concept introduction:

Since $Pb$ was also formed from $U$

  $U_0=U_t+P{b}_t$

Where  $P{b}_t$ is the number of $Pb$ atoms formed after time t.
The decay equation can therefore be written:

  $N_t=N_o{e}^{-\lambda t}$

Given:

Half-life of $U$ = $4.47\times {10}^9$ years
$U$ decays to give $Pb$

Concentration of $U$ in the rock= $105\mu mol$

Concentration of $Pb$ in the rock = $33\mu mol$

To determine:

The age of the rock