All practice pages/Interatomic theory/Elements
Element 67, a lanthanide
Named after Stockholm, it has the highest magnetic strength of any element and powers lasers that break up kidney stones.
Period 6, in the lanthanide row set below the main table. The other lanthanides are tinted, and every cell opens its own article.
Holmium has 67 electrons, one for every proton, so the atom carries no charge. Below are the same 67 electrons written two ways.
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹¹ 5s² 5p⁶ 6s²
Short form: [Xe] 4f¹¹ 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 4f¹¹, 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 4f¹¹, and 2 + 6 + 10 + 11 is 29.
Holmium sits in period 6 and has 6 shells. The period number counts the shells.
The outer shell holds 2 electrons. Those are the ones holmium 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 Ho³⁺ ion in most of its compounds.
One of the less common rare earths, found in monazite, xenotime and gadolinite.
Marc Delafontaine and Jacques-Louis Soret saw its spectral lines in 1878, and Per Teodor Cleve separated its oxide in 1879. Cleve named it after Holmia, the Latin name of his home city, Stockholm.
Pole pieces that concentrate the strongest magnetic fields, since holmium has the highest magnetic strength of any element. Holmium lasers break up kidney stones, holmium oxide glass calibrates spectrophotometers, and holmium absorbs neutrons in reactors.