43 Tc 98

Technetium

transition metal

Properties

Atomic number
43
Atomic mass
98 u
Category
transition metal
Group
7
Period
5
Block
d-block
State (room temp)
Solid
Outer-shell electrons
2
Electronegativity
1.9 (Pauling)
Density
11 g/cm³
Melting point
2156.85 °C
Boiling point
4264.85 °C

Electron configuration

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d⁵

Noble-gas shorthand: [Kr] 4d⁵ 5s²

Electrons per shell: 2, 8, 18, 13, 2 — that's 2 in the outermost shell.

See how electron configuration is built →

Tc
Bohr model — outer-shell electrons in blue

About Technetium

Technetium (/tɛkˈniːʃiəm/) is a chemical element with symbol Tc and atomic number 43. It is the element with the lowest atomic number in the periodic table that has no stable isotopes:every form of it is radioactive. Nearly all technetium is produced synthetically, and only minute amounts are found in nature.

Position in the periodic table

Open the interactive periodic table →

Data compiled from Wikipedia, PubChem, and IUPAC. Source.