Fluorine (F) has 7 valence electrons.
In the periodic table, the number of valence electrons in an element can be determined by its group number (column). Fluorine is in Group 17 (Group VIIA), also known as the halogens. Elements in Group 17 have 7 valence electrons, corresponding to the number of electrons in their outermost energy level (specifically, the 2p orbital).
It's worth noting that the valence electron count can be different for different elements depending on their position in the periodic table. For example, elements in Groups 1 and 2 have 1 and 2 valence electrons, respectively, while elements in Groups 13-18 have 3-8 valence electrons.
So, in the case of fluorine, it has 7 valence electrons, allowing it to readily form a single covalent bond by sharing one electron or gain one electron to achieve a stable noble gas configuration.