Question: what is a molecule what is the difference between a diatomic molecule and a triatomic molecule?
Answer: It is made of two atoms and is called a diatomic molecule. A crystal of NaCl(s) is not a molecule: it is an ionic lattice made up of an indeterminate number of atoms. Carbon dioxide is a molecule made of two oxygen atoms bonded to a carbon atom. It contains three atoms and is called a triatomic molecule.