IB CHEMISTRY

2.2.5 Bond Polarity

Unequal sharing of electrons due to electronegativity differences.

Electronegativity Difference (Δχ)

When two atoms bond, the atom with higher electronegativity attracts the shared electrons more strongly, acquiring a partial negative charge (δ⁻).

Non-Polar Covalent
Equal sharing
Δχ 0.0 - 0.4
Polar Covalent
Unequal sharing (Dipole)
Δχ 0.5 - 1.7
Ionic
Electron transfer
Δχ > 1.8