What is the electronegativity difference in LiF?

Li has an electronegativity of 0.98 and F has an electronegativity of 3.98, giving an EN difference of 3. This classifies the bond as ionic.

Is Lithium Fluoride (LiF) Ionic or Covalent?

Is Lithium Fluoride (LiF) ionic or covalent?

LiF has the largest EN difference possible between any two elements (3.00). Lithium fully transfers its electron to fluorine.

Formula	LiF
Name	Lithium Fluoride
Bond Type	Ionic
EN Values	Li: 0.98, F: 3.98
EN Difference	3
Electron Behavior	Transfer
Melting Point	845 C (high)
Conductivity	Conducts when molten
Solubility	Slightly soluble in water
Key Concept	Maximum EN difference - most ionic bond possible

Lithium fluoride has the largest EN difference of any common compound. It is extremely ionic.

Li has EN 0.98, F has 3.98. The difference of 3.00 is the maximum for common elements.

Lithium completely transfers its single valence electron to fluorine. The resulting Li+ is tiny and F- is relatively large.

Despite small ion sizes, LiF is only slightly soluble in water because the very high lattice energy makes it hard to dissolve.

See electronegativity values, partial charges, and bond character on interactive 3D molecules.