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

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Answer 1 · 2015-01-08T23:54:36

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

The $A_{r}$ $A_r$ 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 = $6.02 \times 10^{23} m o l^{- 1}$ $6.02xx10^(23)mol^-1$ .

So 208g of lead contain $6.02 \times 10^{23}$ $6.02xx10^23$ atoms.

So 1g of lead contains $\frac{6.02 \times 10^{23}}{208}$ $(6.02xx10^(23))/(208)$ atoms

So 4.77 g of lead contains:

$\frac{6.02 \times 10^{23}}{208} \times 4.77 = 1.38 \times 10^{22}$ $(6.02xx10^(23))/(208)xx4.77= 1.38xx10^22$ atoms.