How many atoms of gold are in 54.5 grams?

1.67x10^23 atoms

Explanation:

From Avogadro's hypothesis, 1mole of any substance contains 6.02x10^23 atoms.

This means that 1mole of gold contains 6.02x10^23 atoms.

1 mole of gold = 197g

197g of gold contains 6.02x10^23 atoms.

Therefore, 54.5g of gold will contain = (54.5 x 6.02x10^23) / 197 = 1.67x10^23 atoms