Erbium (Er)

Erbium is a chemical element of the periodic table with chemical symbol Er and atomic number 68 with an atomic weight of 167.259 u and is classed as lanthanide. Erbium is solid at room temperature.

Holmium Periodic table Thulium

Erbium in the periodic table

Symbol	Er
Atomic number	68
Group	-
Period	6
Block	f
Classification	Lanthanide

Appearance	Silvery white
Color	Silver

Number of protons	68 p⁺
Number of neutrons	99 n⁰
Number of electrons	68 e^-

From Wikipedia, the free encyclopediaErbium 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.

Physical properties

Phase at STP	Solid
Density	9.066 g/cm³
Atomic weight	167.259 u

Thermal properties

Melting point	1802 K 1528.85 °C 2783.93 °F
Boiling point	3141 K 2867.85 °C 5194.13 °F
Heat of vaporization	292.88 kJ/mol

Atomic properties

Electronegativity (Pauling Scale)	1.24
Electron affinity	30.1 kJ/mol
Oxidation states	0, +1, +2, +3 (a basic oxide)
Ionization energies	589.3 kJ/mol 1150 kJ/mol 2194 kJ/mol 4120 kJ/mol

Electron configuration for erbium

Electron configuration

Shorthand configuration

[Xe] 4f¹² 6s²

Electron configuration

Full configuration

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

Electron configuration chart

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

Electrons per shell

2, 8, 18, 30, 8, 2

Valence electrons

2

Valency electrons

3

Bohr model

Figure: Shell diagram of Erbium (Er) atom.

Orbital Diagram

1s

2s

2p

3s

3p

3d

4s

4p

4d

4f

5s

5p

6s

The history of Erbium

Discovery

Carl Gustaf Mosander (1843)

Discovery of erbium

Erbium (for Ytterby, a village in Sweden) was discovered by Carl Gustaf Mosander in 1843. Mosander was working with a sample of what was thought to be the single metal oxide yttria, derived from the mineral gadolinite. He discovered that the sample contained at least two metal oxides in addition to pure yttria, which he named "erbia" and "terbia" after the village of Ytterby where the gadolinite had been found. Mosander was not certain of the purity of the oxides and later tests confirmed his uncertainty. Not only did the "yttria" contain yttrium, erbium, and terbium; in the ensuing years, chemists, geologists and spectroscopists discovered five additional elements: ytterbium, scandium, thulium, holmium, and gadolinium.

Periodic table history

Identifiers

List of unique identifiers for Erbium in various chemical registry databases

CAS Number	7440-52-0
ChemSpider ID	22416
EC number	231-160-1
PubChem CID Number	23980