* Oxygen's Electron Configuration: Oxygen has six electrons in its outer shell, needing two more to achieve a stable octet.

* Hydrogen Bonding: Each hydrogen atom shares one electron with the oxygen atom, forming a single covalent bond.

* Lone Pairs: Oxygen has two lone pairs of electrons that are not involved in bonding.

* Repulsion: The lone pairs on the oxygen atom repel the bonding pairs, pushing the hydrogen atoms closer together.

* Resulting Shape: This repulsion creates a bent or V-shape, where the angle between the two hydrogen atoms is about 104.5 degrees.

In summary: The two lone pairs on the oxygen atom in a water molecule cause a significant repulsion that results in a bent molecular shape.