Answer: option (1) the atomic mass in grams.
Explanation:
1) The atomic mass is the mass in grams of one mole of atoms.
2) Hence, it is always the atomic mass of an element equal to the mass of one mole of atoms of such element. Therefore, the atomic mass of Au is the mass of one moles of atoms of Au.
3) Here are some examples:
i) Atomic mass of gold: 196.67 g/atoms, means that 196.97 grams of Au is one mole of Au.
ii) Atomic mass of hydrogen: 1.008 g/mol, means that 1.008 grams of H is one mole of H.
iii) Atomic mass of oxygen: 15.999 g/mol, means that 15.999 grams of O is one mole of O.
iv) Atomic mass of lead: 207.2 g/mol, means that 207.2 grams of Pb is one mole of Pb.
Now you see it, the atomic mass in grams of an element is equal to one mole of the element.
