# How many moles of Pb is in 9.3 * 10^15 atoms of Pb?

$9.3 \times {10}^{15} \text{atoms Pb}$ make up $\textcolor{b l u e}{1.5 \times {10}^{- 8} \text{mol Pb}}$.
One mole of any element contains $6.022 \times {10}^{23} \text{atoms}$ of that element.
In order to determine how many moles are in a given number of atoms, divide the given number of atoms by $\left(6.022 \times {10}^{23} \text{atoms")/(1"mol}\right)$.
$9.3 \times {10}^{15} \cancel{\text{atoms Pb"xx(1"mol Pb")/(6.022xx10^23cancel"atoms Pb")=1.5xx10^(-8)"mol Pb}}$