“The distribution of electrons into orbitals of an atom is called its electronic configuration”.
The general notation of electronic configuration is where and represents the subshell and and represents the number of electrons present in the subshell as superscript.
Atomic number:
The symbol of Fluorine is .
Atomic number of Fluorine is and it is a part of halogen family.
As the atomic number is equal to the number of electrons present in a neutral element. So, the number of electrons is .