All practice pages/Interatomic theory/Elements
Element 68, a lanthanide
A rare earth that amplifies the light carrying the internet under the oceans.
Period 6, in the lanthanide row set below the main table. The other lanthanides are tinted, and every cell opens its own article.
Erbium has 68 electrons, one for every proton, so the atom carries no charge. Below are the same 68 electrons written two ways.
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹² 5s² 5p⁶ 6s²
Short form: [Xe] 4f¹² 6s², where [Xe] stands for the 54 electrons xenon already has.
That list runs by shell. In the order the subshells fill it reads [Xe] 6s² 4f¹², because a subshell fills by its energy, not by its shell number.
The simple form counts electrons shell by shell. The orbital form says which subshell each one sits in: s holds 2, p holds 6, d holds 10 and f holds 14. Shell 4 here is 4s² 4p⁶ 4d¹⁰ 4f¹², and 2 + 6 + 10 + 12 is 30.
Erbium sits in period 6 and has 6 shells. The period number counts the shells.
The outer shell holds 2 electrons. Those are the ones erbium can lose, gain or share, so they are the ones that decide what it bonds with.
Like the other lanthanides, it gives up three electrons to form the Er³⁺ ion in most of its compounds.
Found in xenotime, gadolinite and euxenite, and in the ion-adsorption clays of southern China.
Carl Gustaf Mosander found it in 1843 in yttria from Ytterby, together with terbium, and it was named after the village.
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.