# How does the chemical structure of water relate to its unique properties?

The geometry of molecules depends on the number of atoms present in the molecule and the angles between bonds in the molecule.

For example, molecules $C {O}_{2}$ and ${H}_{2} O$ both have three atoms. The angle between bonds is 180° in carbon dioxide making this molecule linear. The angle between bonds in water is 104.5° making water a bent molecule.

The shapes of molecules have important implications. One is that even though both C=O bonds and O-H bonds have dipoles, carbon dioxide molecules are non-polar due to their linear shape and water molecules are polar due to their bent shape.

Here is a video which discusses VSEPR theory and molecular geometry.

video from: Noel Pauller

The polarity of water means that it will be able to form hydrogen bonds, have a high surface tension and is a very good solvent.

Check out video of a stream of water being bent - a plastic ruler is used in the demo. The stream of water bends due to the polarity of water molecules.

video from: Noel Pauller

Here is video showing how a paperclip can "float" on water - it's actually being held up by the hydrogen bonds formed between water molecules which give water its surface tension.

video from: Noel Pauller

Hope this helps!