Question

I know this relates to moles, so how do I convert 4.77 g of lead (Pb) to atoms?

Answer 1

You do this by converting the mass in grams into the number of moles.

The `A_r` of lead = 208.

This means that 1 mole of lead has a mass of 208g

The number of atoms in a mole of lead is equal to the Avogadro Constant which = `6.02xx10^(23)mol^-1`.

So 208g of lead contain `6.02xx10^23` atoms.

So 1g of lead contains `(6.02xx10^(23))/(208)` atoms

So 4.77 g of lead contains:

`(6.02xx10^(23))/(208)xx4.77= 1.38xx10^22`atoms.