* Electronegativity Difference: Barium (Ba) is a metal with a low electronegativity, while iodine (I) is a nonmetal with a higher electronegativity. The significant difference in electronegativity between these elements leads to the transfer of electrons, forming ions.

* Formation of Ions: Barium loses two electrons to achieve a stable noble gas configuration, forming the Ba²⁺ cation. Iodine gains one electron each to form the I⁻ anion.

* Electrostatic Attraction: The oppositely charged ions (Ba²⁺ and I⁻) attract each other through electrostatic forces, forming an ionic bond.

Therefore, BaI₂ is an ionic compound.