Chemical Symbol Definition and Examples

One and two letter symbols serve as shorthand for chemical element names.
One and two letter symbols serve as shorthand for chemical element names. Mawardi Bahar / EyeEm / Getty Images

Element names and other words in chemistry may be long and cumbersome to use. For this reason, IUPAC chemical symbols and other shorthand notation are commonly used.

Chemical Symbol Definition

A chemical symbol is a notation of one or two letters representing a chemical element. The exceptions to the one- to two-letter symbol are the temporary element symbols assigned to designate new or to-be-synthesized elements. Temporary element symbols are three letters that are based on the element's atomic number.

Also Known As: element symbol

Examples of Element Symbols

Certain rules apply to element symbols. The first letter is always capitalized, while the second (and third, for unverified elements) is lowercase.

  • H is the chemical symbol for hydrogen.
  • C is the chemical symbol for carbon.
  • Si is the chemical symbol for silicon.
  • Uno was the element symbol for hassium. Uno stands for "unniloctium" or "element 108."

Chemical symbols are found on the periodic table and are used when writing chemical formulas and equations.

Other Chemical Symbols

While the term "chemical symbol" usually refers to an element symbol, there are other symbols used in chemistry. For example, EtOH is a symbol for ethyl alcohol, Me indicates a methyl group, and Ala is the symbol for the amino acid alanine. Pictographs are often used to represent specific hazards in chemistry as another form of chemical symbol. For example, a circle with fire above it indicates an oxidizer.


  • Fontani, Marco; Costa, Mariagrazia; Orna, Mary Virginia (2014). The Lost Elements: The Periodic Table's Shadow Side. Oxford University Press. ISBN 9780199383344.
  • Leal, João P. (2013). "The Forgotten Names of Chemical Elements". Foundations of Science. 19: 175–183. doi:10.1007/s10699-013-9326-y