* Electronegativity Difference: Electronegativity is a measure of an atom's ability to attract electrons in a bond. The greater the electronegativity difference between two atoms, the more likely they are to form an ionic bond.
* Magnesium has an electronegativity of 1.31.
* Chlorine has an electronegativity of 3.16.
The difference is 1.85, which is a significant difference.
* Metal and Nonmetal: Magnesium is a metal, and chlorine is a nonmetal. Metals tend to lose electrons (becoming cations) and nonmetals tend to gain electrons (becoming anions). This difference in electron-sharing behavior strongly favors ionic bond formation.
* Formation of Ions: When magnesium and chlorine react, magnesium loses two electrons to become a +2 ion (Mg²⁺). Chlorine gains one electron to become a -1 ion (Cl⁻). These oppositely charged ions attract strongly, forming an ionic bond.
The Result: The strong attraction between the positively charged magnesium ion (Mg²⁺) and the negatively charged chloride ions (Cl⁻) creates a stable ionic compound, magnesium chloride (MgCl₂).
