In chemistry, a symbol is a code for a chemical element.It is usually derived from the name of the element, often in Latin. This is an example of an atomic symbol. The text boxes explain where the numbers are derived from.or example, He is the symbol for helium (English name, not known in ancient Roman times), Pb for lead (plumbum in Latin), W for tungsten (wolfram in German, not known in Roman times). Only the first letter is capitalized.