Valency of Oxygen (O)
The valency of Oxygen is 2 — it has 6 valence electrons, and it loses them to complete its outer shell.
Teachers call it "one fact, fully handled" — exactly what this page does for Oxygen. The answer sits at the top in bold; scroll for the working, the shell-by-shell breakdown and the two questions students ask most. Need the whole picture instead — history, characteristics, uses, exam questions? The full Oxygen page is one click away.
Counting the valence electrons
From the configuration [He] 2s^2 2p^4, Oxygen's outermost shell carries 6 electrons. These are the electrons shown as dots in electron-dot diagrams — the hands Oxygen uses to hold other atoms.
Position check: Oxygen belongs to group 16 of the periodic table, period 2. For main-group elements in groups 13–18, a quick rule is valency = group number − 10, which gives 6 here.
Valency vs valence electrons
Valence electrons are what you count (6 for Oxygen); valency is what the atom will do to complete its outer shell (2 here). Keep the two words straight and half the periodic-table chapter writes itself.
Students also ask
How do I find the valency of Oxygen from its group?
Oxygen sits in group 16; groups 13–17 follow valency = group − 10, giving 6 (though Oxygen also shows 2).
Why does Oxygen show a fixed valency?
Oxygen has 6 valence electrons and reaches a complete outer shell in one consistent way, so its valency stays fixed at 2.