The symbol or combination of symbols to represent the composition of an element or compound. A chemical formula uses numbers and other symbols to represent the elements that make up a particular compound, including those used as medication. A common example of a chemical formula is, H2O, which represents water (2 atoms of hydrogen plus 1 atom of oxygen equals 1 molecule of water). In clinical medicine, a chemical formula is often used as an abbreviation in a patient’s medical chart.
A method to represent the components of a chemical substance using symbols and numerical values is available. For instance, the composition of water is denoted as H2O. This implies that every water molecule consists of two hydrogen atoms (H2) and a single oxygen atom (O).