There are no chemical elements with the symbol Ff or the symbol E. The symbols for elements are found on the periodic table of elements.
Symbols starting with E include Er for erbium, Es for einsteinium and Eu for europium. Elements with a symbol beginning with F include F for fluorine, Fe for iron, Fl for flerovium, Fm for fermium and Fr for francium. F2 is the formula for fluorine gas, which is diatomic to include two atoms of fluorine. While it is not abbreviated as FF, it may be written as F-F based on its Lewis dot structure. In chemistry, the symbol E is used in equations to represent the activation energy.