## College Physics (4th Edition)

The mass of one aluminum atom is $27.0~u$, so the mass of one mole of aluminum atoms is $27.0~grams$
The mass of one mole of atoms is equal to $N$ grams, where $N$ is the mass of one atom measured in atomic units. In this case, the mass of one aluminum atom is $27.0~u$, so the mass of one mole of aluminum atoms is $27.0~grams$