Valency of Fluorine (F)
The valency of Fluorine is 1 — it has 7 valence electrons, and it loses it to complete its outer shell.
Looking for Fluorine's valency without wading through a whole chapter? Here is the direct answer first, then the tables and derivations examiners want to see. Every number on this page comes from the same engine that powers the interactive table. Need the whole picture instead — history, characteristics, uses, exam questions? The full Fluorine page is one click away.
Counting the valence electrons
From the configuration [He] 2s^2 2p^5, Fluorine's outermost shell carries 7 electrons. These are the electrons shown as dots in electron-dot diagrams — the hands Fluorine uses to hold other atoms.
Position check: Fluorine belongs to group 17 of the periodic table, period 2. For main-group elements in groups 13–18, a quick rule is valency = group number − 10, which gives 7 here.
Valency vs valence electrons
Valence electrons are what you count (7 for Fluorine); valency is what the atom will do to complete its outer shell (1 here). Keep the two words straight and half the periodic-table chapter writes itself.
Students also ask
How do I find the valency of Fluorine from its group?
Fluorine sits in group 17; groups 13–17 follow valency = group − 10, giving 7 (though Fluorine also shows 1).
Why does Fluorine show a fixed valency?
Fluorine has 7 valence electrons and reaches a complete outer shell in one consistent way, so its valency stays fixed at 1.