Technetium

Atomic number

43

Atomic mass (u)

96.90636

Category

Transition metal

Standard state

Solid

Melting point

2156.85 °C (2430 K)

Boiling point

4264.85 °C (4538 K)

Density (g/cm³)

11

Electronegativity (Pauling)

1.9

Electron configuration

[Kr]5s2 4d5

Oxidation states

+7, +6, +4

Atomic radius (pm)

209

First ionization energy (eV)

7.28

Discovery & recognition

Discovery year / period (PubChem)

1937

Discovery credited to (RSC)

Carlo Perrier and Emilio Segrè

Date or period recorded by RSC

1937

Discovery place

Italy (analysis of irradiated material)

An ancient date does not identify a first human discovery. Different references may date observation, isolation and formal recognition differently.

Natural occurrence & production

This radioactive element has no stable isotopes. It is principally obtained through nuclear reactions, although minute natural occurrences are known.

“The metal is produced in tonne quantities from the fission products of uranium nuclear fuel.”

Royal Society of Chemistry · occurrence excerpt ↗

Continue the research

Reference values are not product specifications. Blank values have not been estimated. For superheavy elements, some properties and family assignments are theoretical or incompletely measured.