1. Identify the charges of the ions:
* Aluminum (Al) is in Group 3A, so it forms a +3 ion (Al³⁺).
* Sulfur (S) is in Group 6A, so it forms a -2 ion (S²⁻).
2. Find the least common multiple (LCM) of the charges:
* The LCM of 3 and 2 is 6.
3. Determine the subscripts:
* To achieve a +6 charge, we need two aluminum ions (2 x +3 = +6).
* To achieve a -6 charge, we need three sulfur ions (3 x -2 = -6).
4. Write the formula:
The chemical formula for the ionic compound is Al₂S₃.
