Fluorine is located 7 columns to the right on the periodic table. This means it has 7 valence electrons, and wants to gain 1 more in order to have the full valence shell of 8.
There are 7 valence electrons in the element: Fluorine. The electron configuration for Fluorine is: 1s2 ; 2s2 ; 2p7 There is a 7 at the end of 2p, indicating there are 7 valence electrons.