Technetium (Tc)

Technetium is a chemical element with symbol Tc and atomic number 43. It is the lightest element whose isotopes are all radioactive, none of which are stable.

Atomic Number

43

Atomic Mass

98 u

Category

transition metal

Phase

solid

Density

11.5 g/cm³

Electron Shells

2, 8, 18, 13, 2

Atomic Structure

Protons: 43 • Electrons: 43 • Neutrons: Varies by isotope

Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d⁵

Discovery

1937 • Carlo Perrier, Emilio Segrè