Here's why:

* Polarity: Water molecules are polar, meaning they have a slightly positive end (near the hydrogen atoms) and a slightly negative end (near the oxygen atom). This is due to the uneven sharing of electrons between oxygen and hydrogen.

* Attraction: The positive end of one water molecule is attracted to the negative end of another water molecule. This attraction is called a hydrogen bond.

* Weak, but Many: While individual hydrogen bonds are relatively weak, there are many of them in liquid water. This creates a strong overall attraction between water molecules, which is responsible for water's unique properties.

These hydrogen bonds are what give water its high boiling point, surface tension, and ability to dissolve many substances.