None - yet. However - it has been suggested that 'St' should be used for either Antimony (current symbol Sb) or Tin (current symbol Sn).
O is the the symbol of the element oxygen.
If you meant "element" as in a chemical element, there is no element with the symbol "ef" in the periodic table.
The chemical symbol of einsteinium is Es.
Nitrogen is the seventh element on the periodic table. Its symbol is the capital letter N.
Sn is the symbol for tin. (from Latin: stannum)
There is no element St. The closest match is Sr, which is Strontium.
ClO4- Note that this is not an "element" and hence doesn't have an "element symbol."
The symbol of helium is he
There is no element with symbol a or A even
The chemical symbol for the element Xenon is Xe.
Take the element "Iron" then the symbol for the element is "Fe" and "Fe" is also the symbol for a single atom of the element in a chemical equation.
O is the the symbol of the element oxygen.
B is the symbol for which element?Boron
The symbol for the element Terbium is Tb
The element symbol for barium is Ba.
If you meant "element" as in a chemical element, there is no element with the symbol "ef" in the periodic table.
Potassium, with an Atomic Number of 19, is designated by the symbol 'K'.