A chemical symbol is an abbreviation that we use to indicate an element or an atom of an element. For example, the symbol for mercury is Hg (figure below). We use the same symbol (Hg) to indicate one atom of mercury (microscopic domain) or to label a container of many atoms of the element mercury (macroscopic domain).
The symbols for several common elements and their atoms are listed in the table below. Some symbols are derived from the common name of the element; others are abbreviations of the name in another language. Symbols have one or two letters. To avoid confusion with other notations, only the first letter of a symbol is capitalized. For example, Co is the symbol for the element cobalt, but CO is the notation for the compound carbon monoxide, which contains atoms of the elements carbon (C) and oxygen (O). All known elements and their symbols are in the periodic table in Appendix A.
| Element | Symbol | Element | Symbol |
|---|---|---|---|
| aluminum | Al | iron | Fe (from ferrum) |
| bromine | Br | lead | Pb (from plumbum) |
| calcium | Ca | magnesium | Mg |
| carbon | C | mercury | Hg (from hydrargyrum) |
| chlorine | Cl | nitrogen | N |
| chromium | Cr | oxygen | O |
| cobalt | Co | potassium | K (from kalium) |
| copper | Cu (from cuprum) | silicon | Si |
| fluorine | F | silver | Ag (from argentum) |
| gold | Au (from aurum) | sodium | Na (from natrium) |
| helium | He | sulfur | S |
| hydrogen | H | tin | Sn (from stannum) |
| iodine | I | zinc | Zn |
Traditionally, the discoverer (or discoverers) of a new element ends up naming the element. However, until the name is recognized by the International Union of Pure and Applied Chemistry (IUPAC), the recommended name of the new element is based on the Latin word(s) for its atomic number. For example, element 106 was called unnilhexium (Unh), but is now known as seaborgium (Sg) in honour of Glenn Seaborg, a Nobel Prize winner who was active in the discovery of several heavy elements. Most recently discovered elements are named after scientists or locations.
Visit this site to learn more about IUPAC, the International Union of Pure and Applied Chemistry, and explore its periodic table.