Molecules are formed when two or more atoms chemically bond together. Examples of molecules include O2, H2O and CO2.
To remember what a molecule is, picture a moll (a gangster’s wife or girlfriend) who looks cool (molecule), being guarded by henchmen dressed as atoms. Some are the same as each other, some are different.
The atoms that make up a molecule can be of the same or different elements.
Molecules = any atoms