In chemistry, a
symbol is a code for a
chemical element. It is usually derived from the modern name of the element but for some elements it is derived from the name in
Latin. For example, "He" is the symbol for
helium (English name, not known in
ancient Roman times), "Pb" for
lead (
plumbum in Latin), "Hg" for
mercury (
hydrargyrum in Greek), "W" for
tungsten (
wolfram in German, not known in Roman times). Only the first letter is capitalized.