Atomic Properties of Ho
- Atomic Number of Ho
- 67
- Atomic Mass of Ho
- 164.9300 u
- Electron Configuration
- [Xe] 4f11 6s2
- Electronegativity
- 1.23
- Block
- f-block
- Group
- —
- Period
- 6
Holmium first appeared as an unfamiliar absorption spectrum observed by Marc Delafontaine and Jacques-Louis Soret in 1878. Per Teodor Cleve soon separated related material and named the element for Holmia, the Latin name of Stockholm. The name is geographic; it does not mean Sweden, as an older element record once incorrectly claimed.
A neutral holmium atom has an exceptionally large magnetic moment, giving it one of the strongest magnetic personalities among naturally occurring elements. Researchers use holmium-containing materials in specialized magnetic studies and as a way to shape high magnetic fields. That atomic superlative does not mean a loose piece of holmium is the world's strongest permanent magnet; temperature, crystal structure, and surrounding materials determine macroscopic behavior.
Holmium also works through light. Ho:YAG lasers emit infrared radiation strongly absorbed by water, making them useful in procedures such as fragmenting urinary stones and cutting or removing selected tissue. Here holmium ions are dopants in a yttrium-aluminum-garnet crystal, not the surgical material by themselves. Radioactive holmium-166 can also deliver localized beta radiation in specialized medical research and treatment.
Natural holmium consists of stable holmium-165. The silvery metal is relatively stable in dry air but oxidizes more readily with moisture or heat.
This Luminary has a loud atomic signal and a disciplined engineering voice. Its moment matters only when a material organizes it; its laser matters only when a host crystal and wavelength focus it. Precision turns “extra” into useful.