Valency of Caesium (Cs)
The valency of Caesium is 1 — it has 1 valence electron, and it loses it to complete its outer shell.
This is the fast lane: one page, one fact, zero digressions. Read the quick answer, check the table, and if your exam needs the full derivation, the sections below walk through it step by step — in Bangla and English, like every page here. Need the whole picture instead — history, characteristics, uses, exam questions? The full Caesium page is one click away.
Counting the valence electrons
From the configuration [Xe] 6s^1, Caesium's outermost shell carries 1 electron. These are the electrons shown as dots in electron-dot diagrams — the hands Caesium uses to hold other atoms.
Position check: Caesium belongs to group 1 of the periodic table, period 6.
Valency vs valence electrons
Valence electrons are what you count (1 for Caesium); 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 Caesium from its group?
Caesium sits in group 1; groups 1–2 metals have valency equal to the group number — 1 here.
Why does Caesium show a fixed valency?
Caesium has 1 valence electron and reaches a complete outer shell in one consistent way, so its valency stays fixed at 1.