* Electronegativity Difference: Calcium has a low electronegativity (about 1.0) while Chlorine has a high electronegativity (about 3.0). The difference in electronegativity is quite large (2.0), indicating a strong tendency for Chlorine to attract the shared electrons.
* Transfer of Electrons: Due to this electronegativity difference, Calcium readily loses two electrons to achieve a stable noble gas configuration. Chlorine gains one electron to achieve the same. This transfer of electrons creates a positive calcium ion (Ca²⁺) and a negative chloride ion (Cl⁻).
* Electrostatic Attraction: The opposite charges of the ions then attract each other through electrostatic forces, forming an ionic bond.
In summary, the large electronegativity difference and the transfer of electrons leading to the formation of oppositely charged ions make the bond between Calcium and Chlorine ionic.
