Erbium

Erbium,  ₆₉Er

General properties
Name, symbol	Erbium, Er
Appearance	Silvery-white
Erbium in the periodic table
- ↑ Er ↓ Fm Holmium ← Erbium → Thulium
Atomic number	69
Standard atomic weight (Ar)	167.259(3)
Group, block	, f-block
Period	period 6
Electron configuration	[Xe] 4f12 6s2
per shell	2, 8, 18, 30, 8, 2
Physical properties
Silvery-white
Phase	Solid
Melting point	1802 K ​(1529 °C, ​2784 °F)
Boiling point	3141 K ​(2868 °C, ​​5194 °F)
Density near r.t.	9.066 g/cm3
when liquid, at	8.86 g/cm3
Heat of fusion	19.90 kJ/mol
Heat of	280 kJ/mol
Molar heat capacity	28.12 J/(mol·K)
pressure
Atomic properties
Oxidation states	3, 2, 1 ​(a basic oxide)
Electronegativity	Pauling scale: 1.24
energies	1st: 589.3 kJ/mol 2nd: 1150 kJ/mol 3rd: 2194 kJ/mol
Atomic radius	empirical: 176 pm
Covalent radius	189±6 pm
Miscellanea
Crystal structure	​Hexagonal close-packed (hcp)
Speed of sound thin rod	2830 m/s (at 20 °C)
Thermal expansion	12.2 µm/(m·K) (poly)
Thermal conductivity	14.5 W/(m·K)
Electrical resistivity	0.86·10-6 Ω·m
Magnetic ordering	Paramagnetic
Young's modulus	69.9 GPa
Shear modulus	28.3 GPa
Bulk modulus	44.4 GPa
Poisson ratio	0.237
Vickers hardness	430–700 MPa
Brinell hardness	600–1070 MPa
CAS Registry Number	7440-52-0
History
Naming	After Ytterby (Sweden), where it was mined
Discovery	Carl Gustaf Mosander (1842)

Erbium is a chemical element in the lanthanide series, with symbol Er and atomic number 68.

Properties

Chemical

Erbium metal tarnishes slowly in air and burns readily to form erbium(III) oxide:

4 Er + 3 O₂ → 2 Er₂O₃

Erbium will slowly react with cold water, but the reaction occurs much faster in hot water.

Physical

Erbium is a silvery-white malleable metal. It is stable in air, and does not oxidize as quickly as some other rare-earth metals. Erbium is ferromagnetic below 19 K, antiferromagnetic between 19 and 80 K and paramagnetic above 80 K.

Availability

Erbium can be purchased online. Metallium sells erbium coins.

Preparation

Erbium can be prepared by reducing its oxide or salts with calcium at 1450 °C under argon atmosphere.

Er₂O₃ + 3 Ca → 2 Er + 3 CaO

Projects

• Make erbium compounds
• Erbium(III) chloride
• Erbium glass

Handling

Safety

Erbium's toxicity is similar to that of other lanthanides.

Storage

Erbium should be kept in closed bottles, away from moisture and corrosive vapors.

Disposal

Best to try to recycle it.

References

Relevant Sciencemadness threads

• Very low solubility of erbium oxide in mineral acids