Element Symbol to Name Lookup

How it is calculated

The symbol you type is trimmed and normalised so that the first letter is upper case and the rest lower case, which means fe, Fe and FE all work. It is then looked up in a built-in table of all 118 elements, from hydrogen to oganesson. For a match the tool returns the element name, the atomic number Z (the number of protons, which sets its place in the table) and the atomic mass in unified atomic mass units (u), shown with three decimals. For some radioactive elements the table gives the mass number of a long-lived isotope in square brackets, such as [98] u for technetium, rather than a standard atomic weight. An unknown symbol, a full element name, a formula or a three-letter provisional symbol gives no result. The element name is shown in the page language where a translation exists, so the Turkish page says Demir for iron.

Common mistakes

• Typing the element name (Tungsten, Iron) instead of its symbol. The field expects the one- or two-letter symbol such as W or Fe, and a name gives no result.
• Confusing similar symbols that differ by case or one letter, such as Co (cobalt) and CO (carbon monoxide, which is not an element), or Sn (tin) and S (sulfur). Because capitals are ignored, entering CO is read as Co and returns cobalt.
• Assuming the symbol is based on the English name. W is tungsten, Fe is iron, Na is sodium and K is potassium, all from older Latin or German names.
• Treating the mass as an exact whole number for counting nucleons. It is an averaged atomic weight, so use the atomic number for the number of protons and not the mass.
• Typing provisional or compound symbols (Uue, H2O, NaCl). Only the 118 official one- and two-letter symbols are recognised.