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Holmium, 67Ho
Template:Infobox element/symbol-to-top-image/alt
Pronunciation/ˈhlmiəm/ (HOHL-mee-əm)
Appearancesillery white
Standard atomic weight Ar, std(Ho)164.930328(7)[1]
Holmium in the periodic cairt
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Airn Cobalt Nickel Capper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Siller (element) Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gowd Mercur (element) Thallium Leid (element) Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Ununtrium Flerovium Ununpentium Livermorium Ununseptium Ununoctium


Atomic nummer (Z)67
Groupgroup n/a
Periodperiod 6
Element category  Lanthanide
Electron confeeguration[Xe] 4f11 6s2
Electrons per shell2, 8, 18, 29, 8, 2
Pheesical properties
Phase at STPsolit
Meltin pynt1734 K ​(1461 °C, ​2662 °F)
Bylin pynt2993 K ​(2720 °C, ​4928 °F)
Density (near r.t.)8.79 g/cm3
when liquid (at m.p.)8.34 g/cm3
Heat o fusion17.0 kJ/mol
Heat o vapourisation265 kJ/mol
Molar heat capacity27.15 J/(mol·K)
Vapour pressur
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 1432 1584 (1775) (2040) (2410) (2964)
Atomic properties
Oxidation states0,[2] +1, +2, +3 (a basic oxide)
ElectronegativityPauling scale: 1.23
Atomic radiusempirical: 176 pm
Covalent radius192±7 pm
Colour lines in a spectral range
Spectral lines o holmium
Ither properties
Naitural occurrenceprimordial
Creestal structurhexagonal close-packed (hcp)
Hexagonal close packed creestal structur for holmium
Speed o soond thin rod2760 m/s (at 20 °C)
Thermal expansion(r.t.) (poly) 11.2 µm/(m·K)
Thermal conductivity16.2 W/(m·K)
Electrical resistivity(r.t.) (poly) 814 n Ω·m
Magnetic orderinparamagnetic
Young's modulus64.8 GPa
Shear modulus26.3 GPa
Bulk modulus40.2 GPa
Poisson ratio0.231
Vickers haurdness481 MPa
Brinell haurdness746 MPa
CAS Nummer7440-60-0
DiskiveryMarc Delafontaine (1878)
Main isotopes o holmium
Iso­tope Abun­dance Hauf-life (t1/2) Decay mode Pro­duct
163Ho syn 4570 yr ε 163Dy
164Ho syn 29 min ε 164Dy
165Ho 100% stable
166Ho syn 26.763 h β 166Er
167Ho syn 3.1 h β 167Er
| references

Holmium is a chemical element wi the seembol Ho an atomic nummer 67. Pairt o the lanthanide series, holmium is a rare yird element. Holmium wis discovered bi Swadish chemist Per Theodor Cleve. Its oxide wis first isolatit frae rare yird ores in 1878 an the element wis named efter the ceety o Stockholm.

Elemental holmium is a relatively saft an malleable sillery-white metal. It is too reactive tae be foond uncombined in naitur, but when isolatit, is relatively stable in dry air at ruim temperatur. Houiver, it reacts wi watter an rusts readily, an will an aa burn in air when heatit.

Holmium is foond in the minerals monazite an gadolinite, an is uisually commercially extractit frae monazite uisin ion exchynge techniques. Its compoonds in naiture, an in nearly aw o its laboratory chemistry, are trivalently oxidized, containin Ho(III) ions. Trivalent holmium ions hae fluorescent properties seemilar tae mony ither rare yird ions (while yieldin thair awn set o unique emission licht lines), an holmium ions are sicweys uised in the same wey as some ither rare yirds in certaint laser an gless colorant applications.

Holmium haes the heichest magnetic strength o ony element an tharefore is uised for the polepieces o the strangest static magnets. Acause holmium strangly absorbs neutrons, it is an aa uised in nuclear control rods.

Freemit airtins[eedit | eedit soorce]

  1. Meija, Juris; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305.
  2. Yttrium and all lanthanides except Ce, Pm, Eu, Tm, Yb have been observed in the oxidation state 0 in bis(1,3,5-tri-t-butylbenzene) complexes, see Cloke, F. Geoffrey N. (1993). "Zero Oxidation State Compounds of Scandium, Yttrium, and the Lanthanides". Chem. Soc. Rev. 22: 17–24. doi:10.1039/CS9932200017.