How are compounds related to molecules?

The smallest cohesive unit of matter is an atom. Some
atoms, like those of gold, can exist independently of other atoms. But many atoms have
electron structures that create attractions to other atoms.These attractions can create
chemical bonds, which are created through either the sharing of electrons between two
atoms, or the outright transfer of electrons from one atom to
another.

When two or more atoms bond, we call the bonded
unit a molecule. Some molecules consist of just one type of atom: Hydrogen, oxygen,
chlorine and fluorine gases are all good examples of
this.

If a molecule consists of two or more
different elements, then we call that a compound. Molecules range
from very simple diatomic units like sodium chloride (NaCl), which is common table salt,
up to huge polymers that can include thousands of individual atoms chemically bonded
into a single molecule.