 Some pale gold metal, with a liquid-like texture and lustre, sealed in a glass ampoule |
 A colour spectrumSpectral lines of caesium |
| عمومي خواص |
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| Pronunciation | /ˈsiːziəm/
SEE-zee-əm |
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| Alternative name | cesium (US, informal) |
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| Appearance | pale gold |
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| Caesium پهدوراني جدول کې |
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| اټومي شمیره(Z) | 55 |
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| گروپ,پیریود | group 1 (alkali metals),period 6 |
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| بلاک | s-block |
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| Element category | alkali metal |
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| معياري اټومي وزن (Ar) | کينډۍ:Val[۱] |
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| Electron configuration | [Xe] 6s1 |
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Electrons per shell | 2, 8, 18, 18, 8, 1 |
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| فزیکي خواص |
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| حالت(at STP) | جامد |
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| دويلې کيدو ټکى | 301.7 K (28.5 °C, 83.3 °F) |
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| يشنا ټکی | 944 K (671 °C, 1240 °F) |
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| Density near r.t. | 1.93 g/cm3 |
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| when liquid, at m.p. | 1.843 g/cm3 |
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| Critical point | 1938 K, 9.4 MPa[۲] |
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| Heat of fusion | 2.09 kJ/mol |
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| Heat of vaporization | 63.9 kJ/mol |
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| Molar heat capacity | 32.210 J/(mol·K) |
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| Vapour pressure |
| اټومي خواص |
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| Oxidation states | +1, −1[۳] (a stronglybasic oxide) |
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| Electronegativity | Pauling scale: 0.79 |
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| Ionization energies | - 1st: 375.7 kJ/mol
- 2nd: 2234.3 kJ/mol
- 3rd: 3400 kJ/mol
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| Atomic radius | empirical: 265 pm |
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| Covalent radius | 244±11 pm |
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| Van der Waals radius | 343 pm |
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| Miscellanea |
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| Crystal structure | body-centred cubic (bcc) Bodycentredcubic crystal structure for caesium |
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| Thermal expansion | 97 µm/(m·K) (at 25 °C) |
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| د تودوخې تېرېدنه | 35.9 W/(m·K) |
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| Electrical resistivity | 205 nΩ·m (at 20 °C) |
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| Magnetic ordering | paramagnetic[۴] |
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| Young's modulus | 1.7 GPa |
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| Bulk modulus | 1.6 GPa |
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| Mohs hardness | 0.2 |
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| Brinell hardness | 0.14 MPa |
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| CAS Number | 7440-46-2 |
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| History |
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| Naming | from Latin [caesius]تېروتنه: {{Lang}}: ليکنې چې اېټاليک بڼه لري (لارښود), sky blue, for its spectral colours |
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| Discovery | Robert Bunsen andGustav Kirchhoff (1860) |
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| First isolation | Carl Setterberg (1882) |
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| Mainisotopes of caesium |
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| | references | in Wikidata |
