Later This site tells the story of the history of the universe. Click Earlier and Later to follow the story.
Molecules are groups of atoms held together with covalent bonds.
Molecules play a major part in this story. The first molecules were formed in space. Some atoms which came out of a supernova were too light, and so moved too fast, to glue together with ionic bonds . They traveled out of the star until they were cool enough to attach to a dust grain . There these light atoms met and join together with a new type of bond called a covalent bond.