we have the mass of an aluminum sample =.47g, and the number of atoms in sample =107
Alright - first, find the number of moles of aluminium in that sample, by dividing the mass (0.47g) by the molecular weight of aluminium (26.98). Then, having obtained the number of moles, multiply it by the avogadro's constant (6.023x1023) and you will obtain the number of atoms, and by dividing the mass by the number of atoms, you get the mass of an individual atom.
answer is 0.47/107 so each atom weighs 0.004392523364485981308411214953271g that can be rounded to whatever decimal places you want.
Look up the atomic mass of aluminum on your periodic table, multiply by 107, then divide by .47g?
