Holmium

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Holmium,  67Ho
Holmium2.jpg
General properties
Appearance sillery white
Staundart atomic wecht (Ar, staundart) 164.93033(2)
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
-

Ho

Es
dysprosiumholmiumerbium
Atomic nummer (Z) 67
Group group n/a
Period period 6
Element category   lanthanide
Block f-block
Electron confeeguration [Xe] 4f11 6s2
Electrons per shell
2, 8, 18, 29, 8, 2
Pheesical properties
Phase (at STP) solit
Meltin pynt 1734 K ​(1461 °C, ​2662 °F)
Bylin pynt 2993 K ​(2720 °C, ​4928 °F)
Density (near r.t.) 8.79 g/cm3
when liquid (at m.p.) 8.34 g/cm3
Heat o fusion 17.0 kJ/mol
Heat o vapourisation 265 kJ/mol
Molar heat capacity 27.15 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 states

3, 2, 1

(basic oxide)
Electronegativity Pauling scale: 1.23
Atomic radius empirical: 176 pm
Covalent radius 192±7 pm
Color lines in a spectral range
Miscellanea
Creestal structurhexagonal close-packed (hcp)
Hexagonal close packed creestal structur for holmium
Speed o soond thin rod 2760 m/s (at 20 °C)
Thermal expansion (r.t.) (poly) 11.2 µm/(m·K)
Thermal conductivity 16.2 W/(m·K)
Electrical resistivity (r.t.) (poly) 814 n Ω·m
Magnetic orderin paramagnetic
Young's modulus 64.8 GPa
Shear modulus 26.3 GPa
Bouk modulus 40.2 GPa
Poisson ratio 0.231
Vickers haurdness 481 MPa
Brinell haurdness 746 MPa
CAS Nummer 7440-60-0
History
Diskivery Marc 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 | in Wikidata

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.

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