How many atoms are in 78g of Mg?

To find the number of atoms in 78 grams of magnesium (Mg), first determine the molar mass of magnesium, which is approximately 24.31 g/mol. Then, calculate the number of moles in 78 grams by dividing 78 g by 24.31 g/mol, resulting in about 3.21 moles of Mg. Finally, multiply the number of moles by Avogadro's number (approximately (6.022 \times 10^{23}) atoms/mol) to find that there are about (1.93 \times 10^{24}) atoms in 78 grams of magnesium.