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

Jan 8, 2015

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 = $6.02 \times {10}^{23} m o {l}^{-} 1$.

So 208g of lead contain $6.02 \times {10}^{23}$ atoms.

So 1g of lead contains $\frac{6.02 \times {10}^{23}}{208}$ atoms

So 4.77 g of lead contains:

$\frac{6.02 \times {10}^{23}}{208} \times 4.77 = 1.38 \times {10}^{22}$atoms.