1. Understand the Formula:

* Al₂O₃ represents one molecule of aluminum oxide.

* The subscript '2' indicates there are two aluminum (Al) atoms per molecule.

* The subscript '3' indicates there are three oxygen (O) atoms per molecule.

2. Calculate Atoms Per Molecule:

* Each molecule of Al₂O₃ has 2 + 3 = 5 atoms.

3. Calculate Total Atoms:

* Since we have 3 molecules of Al₂O₃, the total number of atoms is 3 molecules * 5 atoms/molecule = 15 atoms.

Therefore, there are 15 atoms in 3Al₂O₃.