Valency of Technetium (Tc)
The valency of Technetium is 2 — it has 2 valence electrons, and it loses them 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 Technetium page is one click away.
Counting the valence electrons
From the configuration [Kr] 4d^5 5s^2, Technetium's outermost shell carries 2 electrons. For a d-block element the nearby inner "d" subshell can also lend electrons, which is where variable valency comes from.
Position check: Technetium belongs to group 7 of the periodic table, period 5.
Valency vs valence electrons
Valence electrons are what you count (2 for Technetium); 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 Technetium from its group?
Technetium sits in group 7; for this transition group the safe exam answer is its common valency, 2.
Why does Technetium show a fixed valency?
Technetium has 2 valence electrons and reaches a complete outer shell in one consistent way, so its valency stays fixed at 2.