Er
Erbium
Element 68 · Lanthanide
Erbium (Er)
Erbium is a silvery rare-earth metal. Erbium-doped fibre amplifiers carry the internet across oceans.
- Lanthanide
- Period 6
- f-block series
- f-block
- solid at room temperature
Key properties
- Atomic mass
- 167.26
- u
- Electron configuration
- [Xe] 4f12 6s2
- Melting point
- 1,528.9 °C
- 1,802 K
- Boiling point
- 2,867.9 °C
- 3,141 K
- Density
- 9.07 g/cm³
- Electronegativity
- 1.24
- Pauling
- Atomic radius
- 235 pm
- van der Waals
- 1st ionisation energy
- 6.108 eV
Compare with every element:Electronegativity chartAtomic radius chartIonisation energy chartDensity chart of the elementsMelting point chartElectron configuration chart
Did you know?
Notable facts about erbium
- 01
Erbium-doped amplifiers boost light signals in undersea fibre-optic cables.
- 02
Erbium oxide gives glass and porcelain a pink colour.
- 03
Erbium lasers are used for skin resurfacing and dentistry.
Applications
What is erbium used for?
- Fibre-optic amplifiers
- Pink glass and gems
- Medical and dental lasers
- Nuclear control rods
History
Discovery & name origin
Atomic structure
Atomic properties
Atomic structure
Atomic properties
- Atomic number
- 68
- Atomic mass
- 167.26 u
- Group
- Lanthanides (3)
- Period
- 6
- Block
- f-block
- Electron configuration
- [Xe] 4f12 6s2
- Full configuration
- 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f12
- Electrons per shell
- 2, 8, 18, 30, 8, 2
- Electronegativity (Pauling)
- 1.24
- Electron affinity
- —
- Atomic radius (van der Waals)
- 235 pm
- Stable isotopes
- 6
Oxidation states
Highlighted: common oxidation states (+3).
Successive ionisation energies
Energy to remove each electron in turn (kJ/mol). Big jumps show where a new, inner shell begins.
- 1st589.3
- 2nd1,150
- 3rd2,194
- 4th4,120
Physical
Physical properties & colour
Physical
Physical properties & colour
- State at 20 °C
- Solid
- Melting point
- 1,802 K · 1,528.9 °C · 2,783.9 °F
- Boiling point
- 3,141 K · 2,867.9 °C · 5,194.1 °F
- Density
- 9.07 g/cm³
- Molar heat capacity
- 28.12 J/(mol·K)
- Appearance
- Silvery white
- CPK model colour
- Copied
The CPK colour is the convention used for this element’s atoms in molecular models.
FAQ
Erbium questions
What is Er on the periodic table?
Er is the symbol for erbium, element 68 on the periodic table. It sits in period 6, in the f-block, in the lanthanide category, and has an atomic mass of 167.26.
What is the atomic number of erbium?
Erbium has atomic number 68, so every erbium atom has 68 protons in its nucleus. Its symbol is Er and its atomic mass is 167.26.
Who discovered erbium?
Erbium was discovered by Carl Gustaf Mosander in 1843 (Sweden). The name comes from from Ytterby, Sweden.
What is erbium used for?
Erbium is used for: fibre-optic amplifiers; pink glass and gems; medical and dental lasers; nuclear control rods.
Is erbium a metal?
Yes. Erbium is a lanthanide, one of the metallic elements.
What is the electron configuration of erbium?
The electron configuration of erbium is [Xe] 4f12 6s2. Its 68 electrons are arranged in shells as 2, 8, 18, 30, 8, 2.