Periodic TableAll elementsTechnetium
No. 043
Tc
98 u
Element · Transition Metal

Technetium

Technetium (锝, symbol Tc) is chemical element number 43, a Transition Metal in period 5, group 7 of the periodic table, with a standard atomic weight of about 98. First artificially produced element. Used as a radioactive tracer in medical imaging.

Period 5Group 7[Kr] 4d⁵ 5s²

Properties

Atomic number43
SymbolTc
Atomic mass98 u
CategoryTransition Metal
Period5
Group7
Electron configuration[Kr] 4d⁵ 5s²
Electronegativity1.9
Covalent radius147 pm
Density11.5 g/cm³
Melting point2430 K
Boiling point4538 K
DiscoveryPerrier & Segrè, 1937

Overview

First artificially produced element. Used as a radioactive tracer in medical imaging. Technetium (Tc) holds position 43 in the periodic table, a Transition Metal in period 5, group 7. As a transition metal it commonly shows several oxidation states, forms coloured compounds, and is widely used in catalysts and alloys.

With 2 electrons in its outermost shell, Technetium bonds accordingly; full configuration [Kr] 4d⁵ 5s², electronegativity 1.9. At room temperature it is normally a solid (a very high melting point); it melts near 2430 K (2156.9 °C), boils near 4538 K (4264.9 °C), has a density around 11.5 g/cm³.

Common applications range across Medical / Pharma, Nuclear and Research. On the safety side, it carries a high hazard rating. It was first described by Perrier & Segrè in 1937. Use the comparison tool to line it up against other elements.

Electron shells

Tc43

Electrons per shell: 2 · 8 · 18 · 13 · 2

Main uses

Hazard

HighRadioactive

Compounds containing Technetium

No compounds in this knowledge base contain Technetium yet.

Data sources

Atomic mass uses IUPAC (CIAAW) standard atomic weights; the covalent radius is from Cordero et al. (2008). Verify on the RSC Periodic Table, PubChem and Wikipedia. Educational reference only.