A compound is a substance formed when two or more elements chemically combine in fixed ratios. When elements are joined, the atoms no longer retain the propertis of their respective elements, but have different properties depending on the compound they form.
Just like an atom represents the smallest part into which an element can be divided and still retain its chemical and physical properties, a molecule represents the smallest part into which a compound can be divided and still retain its chemical and physical properties.
Therefore, a molecule is to a compound what and atom is to an element. Here are some examples of molecules
Each of these molecules represents the smallest part of their respective compounds, carbon dioxide (