An atom of gold has a mass of 3.271x10-22g. How many atoms of gold are in 5.00 g of gold?:confused:

There is an Avogadro's number of atoms in 1 mole of any substance. That includes gold.

mass\,\div\, \frac {mass}{mole} \,=\,moles

The atomic weight is \frac {mass}{moles} (usually grams/mole) so all you have to do is divide the mass by the atomic weight and you have the number of moles. To find the number of atoms, simply multiply the number of moles by Avogadro's number

moles \,\times\, Avogadro's \,number \, = \, atoms

There isn't even need to use the Avogadro's constant here. This problem is only a proportion problem.

3.271 \times 10^{-22} g -> 1 atom

1 g -> \frac{1}{3.271 \times 10^{-22}} atom

5 g -> \frac{1}{3.271 \times 10^{-22}} \times 5 atoms

Quite right. I didn't read the problem completely.