* Molecular Geometry: NBr3 has a trigonal pyramidal shape. This is due to the nitrogen atom having three bonding pairs and one lone pair of electrons.
* Electronegativity Difference: Bromine is more electronegative than nitrogen. This means the bromine atoms pull the shared electrons in the N-Br bonds closer to themselves, creating partial negative charges (δ-) on the bromine atoms and a partial positive charge (δ+) on the nitrogen atom.
* Dipole Moment: The individual bond dipoles (from the polar N-Br bonds) do not cancel each other out due to the molecule's asymmetrical shape. They create a net dipole moment, pointing towards the bromine atoms.
Therefore, NBr3 has a permanent dipole moment, making it a polar molecule.
