If the atoms differ in their attraction for electrons, a polar-covalent bond will be formed.  Water is an example of a molecule with this type of bond...the following illustration attempts to show how the bond is distorted creating partial positive and negative charges on the atoms.

The attraction of electrons to the nucleus of an atom is a very important property of atoms and is called electronegativity. The difference in electronegativity between bonded atoms determines the bond polarity.

Describe the type of bond shown by a dash in the following examples...

H-H answer

H-CH₃ answer

H-NH₂ answer

Na-O-Na answer

Na-Br answer

K-OH answer

H-OH answer

F-CH₃ answer