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Erbium Facts

Chemical & Physical Properties


This is a photo of a piece of pure erbium.

This is a photo of a piece of pure erbium. Erbium is a soft silvery metal that does not oxidize in air as quickly as most of the rare earths.

Tomihahndorf, Free Documentation License
Periodic Table of the Elements


Atomic Number: 68

Symbol: Er

Atomic Weight: 167.26

Discovery: Carl Mosander 1842 or 1843 (Sweden)

Electron Configuration: [Xe] 4f12 6s2

Word Origin: Ytterby, a town in Sweden

Isotopes: Natural erbium is a mix of six stable isotopes. Nine radioactive isotopes are also recognized.

Properties: The melting point of erbium is 159°C, boiling point is 2863°C, specific gravity is 9.066 (25°C), and valence is 3. Pure erbium metal is soft and malleable with a bright silvery metallic luster. The metal is fairly stable in air.

Uses: Erbium has nuclear and metallurgical uses. It may be added to other metals to lower hardness and improve workability. Erbium oxide is used as a pink colorant in glass and porcelain glaze.

Element Classification: Rare Earth (Lanthanide)

Density (g/cc): 9.06

Melting Point (K): 1802

Boiling Point (K): 3136

Appearance: soft, malleable, silvery metal

Atomic Radius (pm): 178

Atomic Volume (cc/mol): 18.4

Covalent Radius (pm): 157

Ionic Radius: 88.1 (+3e)

Specific Heat (@20°C J/g mol): 0.168

Evaporation Heat (kJ/mol): 317

Pauling Negativity Number: 1.24

First Ionizing Energy (kJ/mol): 581

Oxidation States: 3

Lattice Structure: Hexagonal

Lattice Constant (Å): 3.560

Lattice C/A Ratio: 1.570

References: Los Alamos National Laboratory (2001), Crescent Chemical Company (2001), Lange's Handbook of Chemistry (1952), CRC Handbook of Chemistry & Physics (18th Ed.)

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