Question

The common water molecule is polar because

Answer 1

in chemistry, polarity is defined as the separation of charges. Water molecules are made up of an oxygen and 2 hydrogen atoms. Oxygen is more electronegative than hydrogen and so the electrons will be more often drawn towards the oxygen atom than the hydrogens.

since electrons are negatively charged, the oxygen atom will have a partial negative charge (denoted by a delta negative sign) and the hydrogens a partial positive (denoted by a delta positive sign). This separation induces a net dipole moment, a sum of individual dipoles (which are vectors, meaning they have, both, direction and magnitude) .