68 Er 167.259

Erbium

lanthanide

Properties

Atomic number
68
Atomic mass
167.259 u
Category
lanthanide
Group
f-block
Period
6
Block
f-block
State (room temp)
Solid
Outer-shell electrons
2
Electronegativity
1.24 (Pauling)
Density
9.066 g/cm³
Melting point
1528.85 °C
Boiling point
2867.85 °C

Electron configuration

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹²

Noble-gas shorthand: [Xe] 4f¹² 6s²

Electrons per shell: 2, 8, 18, 30, 8, 2 — that's 2 in the outermost shell.

See how electron configuration is built →

Er
Bohr model — outer-shell electrons in blue

About Erbium

Erbium is a chemical element in the lanthanide series, with symbol Er and atomic number 68. A silvery-white solid metal when artificially isolated, natural erbium is always found in chemical combination with other elements on Earth. As such, it is a rare earth element which is associated with several other rare elements in the mineral gadolinite from Ytterby in Sweden, where yttrium, ytterbium, and terbium were discovered.

Position in the periodic table

Open the interactive periodic table →

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