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68Er167.26

Element 68, a lanthanide

Erbium

A rare earth that amplifies the light carrying the internet under the oceans.

At a glance

Symbol
Er
Atomic number
68
Average atomic mass
167.26
Group
none; it sits in the lanthanide row below the table
Period
6
Family
lanthanide
Electron configuration
[Xe] 4f¹² 6s²
Electronegativity
1.24
Common ions
Er³⁺, pink in solution

On the table

Periodic table with Erbium highlighted123456789101112131415161718123456757-7189-103HHeLiBeBCNOFNeNaMgAlSiPSClArKCaScTiVCrMnFeCoNiCuZnGaGeAsSeBrKrRbSrYZrNbMoTcRuRhPdAgCdInSnSbTeIXeCsBaLaCePrNdPmSmEuGdTbDyHoErTmYbLuHfTaWReOsIrPtAuHgTlPbBiPoAtRnFrRaAcThPaUNpPuAmCmBkCfEsFmMdNoLrRfDbSgBhHsMtDsRgCnNhFlMcLvTsOg

Period 6, in the lanthanide row set below the main table. The other lanthanides are tinted, and every cell opens its own article.

Electrons and bonding

Like the other lanthanides, it gives up three electrons to form the Er³⁺ ion in most of its compounds.

Properties

State at 25 °C
solid
What it looks like
soft, silvery metal
Melting point
1529 °C
Boiling point
2868 °C
Density
9.07 g/cm³

Where it is found

Found in xenotime, gadolinite and euxenite, and in the ion-adsorption clays of southern China.

Discovery and name

Carl Gustaf Mosander found it in 1843 in yttria from Ytterby, together with terbium, and it was named after the village.

What it is used for

Erbium-doped fiber amplifiers boost the light signals in long-distance fiber-optic cables, including those under the oceans, without converting them to electricity. Erbium also colors glass and cubic zirconia pink, and erbium lasers are used in skin treatments and dentistry.

In compounds

Er₂O₃erbium oxide, pinkErCl₃erbium chlorideErF₃erbium fluoride