Here's why:

* Electronegativity Difference: Aluminum (Al) is a metal with a low electronegativity, while Bromine (Br) is a nonmetal with a high electronegativity. The significant difference in electronegativity between the two elements leads to the transfer of electrons from aluminum to bromine.

* Formation of Ions: Aluminum loses three electrons to become a positively charged aluminum ion (Al³⁺), while bromine gains one electron each to form negatively charged bromide ions (Br^-).

* Electrostatic Attraction: The oppositely charged ions are then held together by strong electrostatic forces, forming an ionic bond.

Therefore, Aluminum Bromide is a classic example of an ionic compound.