Moles of aluminum carbonate = Mass / Molar mass = 47.6 g / 233.99 g molâ’1 =0.203 mol To find moles of oxygen: In each mole of the carbonate there are 9 moles of oxygen And thus there are 9 Ă— 0.203 moles of oxygen in the given quantity. = 1.83 moles of oxygen Within one mole of oxygen, we have 6.022 x 10^23 atoms Amount of atoms within 1.827 moles of oxygen = 1.83 x 6.022 x 10^23 = 1.10 x 10^24 atoms