Argon, 18Ar![Template:Infobox element/symbol-to-top-image/alt](//upload.wikimedia.org/wikipedia/commons/thumb/8/87/Argon_discharge_tube.jpg/220px-Argon_discharge_tube.jpg) |
Argon |
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Pronunciation | (AR-gon) |
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Appearance | colourless gas exhibitin a laylock/violet glowe whan placed in a heich voltage electric field |
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Standard atomic weight Ar, std(Ar) | [7001397920000000000♠39.792, 7001399630000000000♠39.963] conventional: 7001399480000000000♠39.948 |
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Argon in the periodic cairt |
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Atomic nummer (Z) | 18 |
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Group | group 18 (noble gases) |
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Period | period 3 |
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Block | p-block |
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Element category | Noble gas |
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Electron confeeguration | [Ne] 3s2 3p6 |
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Electrons per shell | 2, 8, 8 |
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Pheesical properties |
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Phase at STP | gas |
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Meltin pynt | 83.81 K (−189.34 °C, −308.81 °F) |
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Bylin pynt | 87.302 K (−185.848 °C, −302.526 °F) |
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Density (at STP) | 1.784 g/L |
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whan liquid (at b.p.) | 1.40 g/cm3 |
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Treeple pynt | 83.8058 K, 68.89[1] kPa |
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Creetical pynt | 150.687 K, 4.863[1] MPa |
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Heat o fusion | 1.18 kJ/mol |
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Heat o vapourisation | 6.43 kJ/mol |
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Molar heat capacity | 5R/2 = 20.786 (Cp) J/(mol·K) |
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Vapour pressurP (Pa) | 1 | 10 | 100 | 1 k | 10 k | 100 k |
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at T (K) | | 47 | 53 | 61 | 71 | 87 |
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Atomic properties |
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Oxidation states | 0 |
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Electronegativity | Pauling scale: no data |
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Ionisation energies | |
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Covalent radius | 106±10 pm |
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Van der Waals radius | 188 pm |
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Colour lines in a spectral rangeSpectral lines o argon |
Ither properties |
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Naitural occurrence | primordial |
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Creestal structur | face-centred cubic (fcc) |
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Speed o soond | (gas, 27 °C) 323 m/s |
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Thermal conductivity | 17.72×10−3 W/(m·K) |
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Magnetic orderin | diamagnetic[2] |
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CAS Nummer | 7440–37–1 |
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History |
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Diskivery | Lord Rayleigh an William Ramsay (1894) |
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First isolation | Lord Rayleigh an William Ramsay (1894) |
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Main isotopes o argon |
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Decay modes in parentheses is predict, but hisna yet been observed |
| references |
style="text-align:left"| |
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| in | calc from C | diff | report | ref |
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C | −189.34 | — | — | | |
K | 83.81 | 83.81 | 0 | | |
F | −308.81 | −308.81 | 0 | | |
WD | -189.34 !-189.34 Celsius ![Edit this at Wikidata](//upload.wikimedia.org/wikipedia/commons/thumb/7/73/Blue_pencil.svg/10px-Blue_pencil.svg.png) | | | |
input | C: −189.34, K: 83.81, F: −308.81 |
comment | |
style="text-align:left"| |
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| in | calc from C | diff | report | ref |
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C | −185.848 | — | — | | |
K | 87.302 | 87.302 | 0 | | |
F | −302.526 | −302.526 | 0 | | |
WD | -185.85 !-185.85 Celsius ![Edit this at Wikidata](//upload.wikimedia.org/wikipedia/commons/thumb/7/73/Blue_pencil.svg/10px-Blue_pencil.svg.png) | | | |
input | C: −185.848, K: 87.302, F: −302.526 |
comment | |
References
Thir references will appear in the airticle, but this list appears anerly on this page.
- ↑ a b Haynes, William M., ed. (2011). CRC Handbook of Chemistry and Physics (92nt ed.). CRC Press. p. 4.121. ISBN 1439855110.
- ↑ Magnetic susceptibility of the elements and inorganic compounds, in Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5.