How many moles of lead are in #1.50 * 10^12# atoms of lead?
Before doing any calculations, it's worth noting that atoms do not contain moles, it's the other way around.
A mole is simply a collection of atoms. More specifically, you need to have exactly
In your case, you must determine how many moles of lead would contain
Well, if you know that one mole of lead must contain
#1.50 * 10^12 color(red)(cancel(color(black)("atoms of Pb"))) * "1 mole Pb"/(6.022 * 10^(23)color(red)(cancel(color(black)("atoms of Pb")))) = color(green)(2.49 * 10^(-12)"moles Pb")#