The relationship between atoms and molecules is the way molecules are made up of atoms. Atoms that are in groups of two or more are called molecules.
Atoms are the basis for life and they are the smallest part of any type of element. Everything is comprised of atoms and there is nothing smaller than an atom. Anything that is smaller than an atom is no longer a part of the original element. Most, if not all, atoms stay together in groups of two or more. These groupings, called molecules, are what make elements a complex combination of different components.
There are many different things that molecules do to help form bigger and better elements. A combination of molecules together makes a compound. Water, for example, is made up of hydrogen and oxygen elements, which makes it a type of compound. Compounds are complex systems because they are one element made up of two molecules, which are made up of two or more atoms. One easy way to determine whether something is an atom, compound or molecule is that atoms generally do not have names until they are formed into molecules. Molecules generally have names, such as hydrogen or oxygen, and they form together to make things that have true names, such as water.