The atomic number of fluorine is 9.
Atomic number is the number of protons present in the element. The number of electrons and protons is same in a neutral element.
The given ion of fluorine is [tex]^{19}F^{-}[/tex]. It represents a uninegative anion with a mass number of 19.
It is an anion with a charge of -1, this means that there is an additional electron in the ion. The number of electrons in this ion are 9 + 1 = 10 electrons
The correct answer will be C. 10 electrons
