* Electro negativity difference: Barium (Ba) is a metal with low electronegativity, while Fluorine (F) is a non-metal with high electronegativity. The difference in electronegativity between barium and fluorine is significant, leading to a complete transfer of electrons from barium to fluorine.

* Formation of ions: Barium loses two electrons to become a positively charged ion (Ba²⁺), while each fluorine atom gains one electron to become a negatively charged ion (F⁻).

* Electrostatic attraction: The oppositely charged ions (Ba²⁺ and F⁻) are held together by strong electrostatic forces, forming an ionic bond.

In summary: The significant difference in electronegativity between barium and fluorine, resulting in the formation of ions and their electrostatic attraction, classifies BaF₂ as an ionic compound.