1. Determine the Charges:
* Aluminum (Al) is in Group 3A, so it forms a +3 ion (Al³⁺).
* Chlorine (Cl) is in Group 7A, so it forms a -1 ion (Cl⁻).
2. Balance the Charges:
To form a neutral compound, the positive and negative charges must balance. You need three chloride ions (3 x -1 = -3) to balance the +3 charge of the aluminum ion.
3. Write the Formula:
The formula is AlCl₃.
Therefore, the chemical formula of the ionic compound formed between aluminum and chlorine is AlCl₃.
