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Holmium |
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Pronunciation | (HOHL-mee-əm) |
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Appearance | sillery white |
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Standard atomic weight Ar, std(Ho) | 7002164930328000000♠164.930328(7)[1] |
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Holmium in the periodic cairt |
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Atomic nummer (Z) | 67 |
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Group | group n/a |
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Period | period 6 |
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Block | f-block |
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Element category | Lanthanide |
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Electron confeeguration | [Xe] 4f11 6s2 |
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Electrons per shell | 2, 8, 18, 29, 8, 2 |
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Pheesical properties |
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Phase at STP | solit |
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Meltin pynt | 1734 K (1461 °C, 2662 °F) |
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Bylin pynt | 2993 K (2720 °C, 4928 °F) |
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Density (near r.t.) | 8.79 g/cm3 |
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when liquid (at m.p.) | 8.34 g/cm3 |
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Heat o fusion | 17.0 kJ/mol |
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Heat o vapourisation | 265 kJ/mol |
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Molar heat capacity | 27.15 J/(mol·K) |
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Vapour pressur
P (Pa) |
1 |
10 |
100 |
1 k |
10 k |
100 k |
at T (K) |
1432 |
1584 |
(1775) |
(2040) |
(2410) |
(2964) |
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Atomic properties |
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Oxidation states | 0,[2] +1, +2, +3 (a basic oxide) |
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Electronegativity | Pauling scale: 1.23 |
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Atomic radius | empirical: 176 pm |
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Covalent radius | 192±7 pm |
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Spectral lines o holmium |
Ither properties |
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Naitural occurrence | primordial |
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Creestal structur | hexagonal close-packed (hcp) |
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Speed o soond thin rod | 2760 m/s (at 20 °C) |
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Thermal expansion | (r.t.) (poly) 11.2 µm/(m·K) |
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Thermal conductivity | 16.2 W/(m·K) |
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Electrical resistivity | (r.t.) (poly) 814 n Ω·m |
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Magnetic orderin | paramagnetic |
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Young's modulus | 64.8 GPa |
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Shear modulus | 26.3 GPa |
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Bulk modulus | 40.2 GPa |
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Poisson ratio | 0.231 |
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Vickers haurdness | 481 MPa |
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Brinell haurdness | 746 MPa |
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CAS Nummer | 7440-60-0 |
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History |
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Diskivery | Marc Delafontaine (1878) |
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Main isotopes o holmium |
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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 |
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| references |