2.2.5 Bond Polarity

• Polarity is related to the way the electrons are distributed withinonds and molecules

  • Shared pairs of electrons are not necessarily shared equally between two atoms

• Bond polarity is resulted from the difference of Electronegativity of bonded atoms

• For $F_2$--> same bond strength ( Pure covalent bond )

  • Non-polar

  • No dipole moment

• For $HF$ $\because$$EN_F>EN_H$, so flourine pulls more than Hydrogen

  • This is a Polar Covalent bond, with one atom adopting a partial negative charge $\delta -$, and hydrogen adopting a positive charge $\delta +$.

Separation of charges between two non-idential bonded atoms is called the dipole moment. This moment is represented through a vector along the bond.

The vector starts as a plus sign at the less electronegative side and points to the more electronegative atom in the bond.