43Tc[98]

Technetium (Tc) – element 43

Technetium is a chemical element with the symbol Tc and atomic number 43. It is a transition metal in group 7, period 5 of the periodic table (d-block), and is a solid at room temperature.

Technetium (Tc) has atomic number 43, atomic mass [98] and electron configuration [Kr] 4d5 5s2.

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Technetium facts

SymbolTc
Atomic number43
Atomic mass[98]
Categorytransition metal
Groupgroup 7
Period5
Blockd-block
Phase at 20 °CSolid
Electron configuration1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d5
Noble-gas notation[Kr] 4d5 5s2
Electrons per shell2, 8, 18, 13, 2

Bohr model and shells

Tc

Technetium has 43 electrons in 5 shells: 2, 8, 18, 13, 2. Full configuration and noble-gas notation are in the table; work out any element or ion with the electron configuration calculator.

Physical and atomic properties

Melting point2430 K (2156.8 °C)
Boiling point4538 K (4264.9 °C)
Density11 g/cm³
Electronegativity (Pauling)1.9
Electron affinity53 kJ/mol
Ionization energies702, 1470, 2850 kJ/mol (1st, 2nd, 3rd)
Molar heat capacity24.27 J/(mol·K)
Discovered byEmilio Segrè

Use the atomic mass in the molar mass calculator for any formula containing Tc.

Position in the periodic table

HydrogenHHeliumHeLithiumLiBerylliumBeBoronBCarbonCNitrogenNOxygenOFluorineFNeonNeSodiumNaMagnesiumMgAluminiumAlSiliconSiPhosphorusPSulfurSChlorineClArgonArPotassiumKCalciumCaScandiumScTitaniumTiVanadiumVChromiumCrManganeseMnIronFeCobaltCoNickelNiCopperCuZincZnGalliumGaGermaniumGeArsenicAsSeleniumSeBromineBrKryptonKrRubidiumRbStrontiumSrYttriumYZirconiumZrNiobiumNbMolybdenumMoTechnetiumTcRutheniumRuRhodiumRhPalladiumPdSilverAgCadmiumCdIndiumInTinSnAntimonySbTelluriumTeIodineIXenonXeCesiumCsBariumBaLanthanumLaCeriumCePraseodymiumPrNeodymiumNdPromethiumPmSamariumSmEuropiumEuGadoliniumGdTerbiumTbDysprosiumDyHolmiumHoErbiumErThuliumTmYtterbiumYbLutetiumLuHafniumHfTantalumTaTungstenWRheniumReOsmiumOsIridiumIrPlatinumPtGoldAuMercuryHgThalliumTlLeadPbBismuthBiPoloniumPoAstatineAtRadonRnFranciumFrRadiumRaActiniumAcThoriumThProtactiniumPaUraniumUNeptuniumNpPlutoniumPuAmericiumAmCuriumCmBerkeliumBkCaliforniumCfEinsteiniumEsFermiumFmMendeleviumMdNobeliumNoLawrenciumLrRutherfordiumRfDubniumDbSeaborgiumSgBohriumBhHassiumHsMeitneriumMtDarmstadtiumDsRoentgeniumRgCoperniciumCnNihoniumNhFleroviumFlMoscoviumMcLivermoriumLvTennessineTsOganessonOg

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Frequently asked questions

What is the atomic mass of technetium?

The atomic mass of technetium is [98] (mass number of its longest-lived isotope, since it has no stable isotope).

What is the electron configuration of technetium?

Technetium has 43 electrons: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d⁵, or [Kr] 4d⁵ 5s² in noble-gas notation. Electrons per shell: 2, 8, 18, 13, 2.

Is technetium a metal?

Yes. Technetium is a transition metal.

Where is technetium on the periodic table?

Technetium is in group 7, period 5, in the d-block.

Data: Periodic-Table-JSON (CC BY-SA 3.0); standard atomic weights from IUPAC (abridged). Values in brackets are the mass number of the longest-lived isotope.