* Titanium (Ti) is a metal, and metals tend to lose electrons to form positive ions (cations).

* Chlorine (Cl) is a nonmetal, and nonmetals tend to gain electrons to form negative ions (anions).

In TiCl₂, titanium loses two electrons to become Ti²⁺, while chlorine gains one electron each to become Cl⁻. The electrostatic attraction between the positively charged titanium ion and the negatively charged chloride ions forms the ionic bond.