What’s a molecule?

A cartoon drawing of water molecules. Each round ball represents an atom. The smaller round balls are hydrogen atoms and the larger balls are oxygen atoms. Click on image for full size (171K GIF) Courtesy of Corel

Everything around us is made of groups of atoms connected together into packages called molecules.

Molecules are made from atoms of one or more elements. Some molecules are made of only one type of atom. Other molecules are very large and are made of hundreds of atoms.

Even large molecules are so small that you would not be able to see only one molecule of something. But when thousands of molecules are together, they might look like a glass of water, a tree or even your computer screen!