Empirical formula

In chemistry, the empirical formula of a chemical is a simple expression of
the relative number of each type of atom (element) in it. An empirical
formula makes no reference to isomerism, structure, or absolute number of
atoms. The term empirical refers to the process of elemental analysis, an
analytical technique used to determine the relative percent composition of a
pure chemical substance by element.

For example, hexane could have a chemical formula of CH3CH2CH2CH2CH2CH3,
implying that it has a straight chain structure, 6 carbon atoms, and 14 hydrogen
atoms. However the empirical formula for the same molecule would be C3H7.