Water is called a polar molecule because one end of the molecule is slightly negative (near the oxygen atom) while the other end is slightly positive (near the hydrogen atoms), giving it two “poles” of charge.

What “polar” means here

“Polar” in chemistry means a molecule has an uneven distribution of electrical charge, like a tiny bar magnet with a positive end and a negative end.

In water, this comes from two key ideas: unequal sharing of electrons and the bent shape of the molecule.

Unequal sharing of electrons

  • Oxygen is more electronegative than hydrogen, so it pulls the shared electrons in the O–H bonds closer to itself.
  • Because electrons are negatively charged, the oxygen side becomes slightly negative, and the hydrogen side becomes slightly positive.
  • This creates partial charges: we often write these as δ− on oxygen and δ+ on each hydrogen.

Why the shape matters

  • The water molecule is not a straight line; it has a bent geometry (like a V shape), with oxygen at the point and the hydrogens at the tips.
  • Because of this bent shape, the partial charges do not cancel out; instead, they add up to give the molecule an overall dipole (a distinct positive side and negative side).

Connecting to “distribution of charges” in the diagram

If your diagram shows negative charge (often red or “−”) clustered around oxygen and positive charge (often blue or “+”) near the hydrogens, that picture is literally showing:

  • A negative region at one end.
  • A positive region at the other end.

Since a molecule with a separated positive end and negative end is defined as polar, this distribution of charge is why the water molecule is called polar.

TL;DR: The diagram shows electrons pulled toward oxygen, making that end slightly negative and the hydrogen end slightly positive; with the bent shape, those charges don’t cancel, so water has two poles and is therefore polar.

Information gathered from public forums or data available on the internet and portrayed here.