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Beryllium |
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Pronunciation | (bə-RIL-ee-əm) |
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Appearance | white-gray metallic |
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Standard atomic weight Ar, std(Be) | 7000901218310000000♠9.0121831(5)[1] |
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Beryllium in the periodic cairt |
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Atomic nummer (Z) | 4 |
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Group | group 2 (alkaline yird metals) |
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Period | period 2 |
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Block | s-block |
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Element category | Alkaline yird metal |
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Electron confeeguration | [He] 2s2 |
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Electrons per shell | 2, 2 |
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Pheesical properties |
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Phase at STP | solit |
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Meltin pynt | 1560 K (1287 °C, 2349 °F) |
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Bylin pynt | 3243 K (2970 °C, 5378 °F) |
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Density (near r.t.) | 1.85 g/cm3 |
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when liquid (at m.p.) | 1.690 g/cm3 |
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Creetical pynt | 5205 K, MPa (extrapolatit) |
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Heat o fusion | 12.2 kJ/mol |
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Heat o vapourisation | 292 kJ/mol |
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Molar heat capacity | 16.443 J/(mol·K) |
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Vapour pressur
P (Pa) |
1 |
10 |
100 |
1 k |
10 k |
100 k |
at T (K) |
1462 |
1608 |
1791 |
2023 |
2327 |
2742 |
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Atomic properties |
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Oxidation states | 0,[2] +1,[3] +2 (an amphoteric oxide) |
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Electronegativity | Pauling scale: 1.57 |
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Ionisation energies | - 1st: 899.5 kJ/mol
- 2nd: 1757.1 kJ/mol
- 3rd: 14848.7 kJ/mol
- (more)
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Atomic radius | empirical: 112 pm |
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Covalent radius | 96±3 pm |
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Van der Waals radius | 153 pm |
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Spectral lines o beryllium |
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 | 12890 m/s (at r.t.)[4] |
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Thermal expansion | 11.3 µm/(m·K) (at 25 °C) |
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Thermal conductivity | 200 W/(m·K) |
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Electrical resistivity | 36 nΩ·m (at 20 °C) |
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Magnetic orderin | diamagnetic |
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Young's modulus | 287 GPa |
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Shear modulus | 132 GPa |
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Bulk modulus | 130 GPa |
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Poisson ratio | 0.032 |
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Mohs haurdness | 5.5 |
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Vickers haurdness | 1670 MPa |
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Brinell haurdness | 590–1320 MPa |
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CAS Nummer | 7440-41-7 |
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History |
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Diskivery | Louis Nicolas Vauquelin (1797) |
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First isolation | Friedrich Wöhler & Antoine Bussy (1828) |
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Main isotopes o beryllium |
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| references |