Caesium, 55Cs |
| Caesium |
|---|
| Pronunciation | (SEE-zee-əm) |
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| Appearance | sillery gowd |
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| Standard atomic weight Ar, std(Cs) | 7002132905451960000♠132.90545196(6)[1] |
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| Caesium in the periodic cairt |
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|
|
| Atomic nummer (Z) | 55 |
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| Group | group 1 (alkali metals) |
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| Period | period 6 |
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| Block | s-block |
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| Element category | Alkali metal |
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| Electron confeeguration | [Xe] 6s1 |
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| Electrons per shell | 2, 8, 18, 18, 8, 1 |
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| Pheesical properties |
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| Phase at STP | solit |
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| Meltin pynt | 301.59 K (28.44 °C, 83.19 °F) |
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| Bylin pynt | 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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| Creetical pynt | 1938 K, 9.4 MPa |
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| Heat o fusion | 2.09 kJ/mol |
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| Heat o vapourisation | 63.9 kJ/mol |
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| Molar heat capacity | 32.210 J/(mol·K) |
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Vapour pressur
| P (Pa)
|
1
|
10
|
100
|
1 k
|
10 k
|
100 k
|
| at T (K)
|
418
|
469
|
534
|
623
|
750
|
940
|
|
| Atomic properties |
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| Oxidation states | −1, +1[2] strangly basic |
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| Electronegativity | Pauling scale: 0.79 |
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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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 Colour lines in a spectral rangeSpectral lines o caesium |
| Ither properties |
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| Naitural occurrence | primordial |
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| Creestal structur | body-centred cubic (bcc) |
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| Thermal expansion | 97 µm/(m·K) (at 25 °C) |
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| Thermal conductivity | 35.9 W/(m·K) |
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| Electrical resistivity | 205 n Ω·m (at 20 °C) |
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| Magnetic orderin | paramagnetic[3] |
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| Young's modulus | 1.7 GPa |
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| Bulk modulus | 1.6 GPa |
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| Mohs haurdness | 0.2 |
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| Brinell haurdness | 0.14 MPa |
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| CAS Nummer | 7440-46-2 |
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| History |
|---|
| Diskivery | Robert Bunsen an Gustav Kirchhoff (1860) |
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| First isolation | Carl Setterberg (1882) |
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| Main isotopes o caesium |
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|
|
| | references |
| style="text-align:left"|
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in
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calc from C
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diff
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report
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ref
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| C
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28.44
|
—
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—
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|
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| K
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301.59
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301.59
|
0
|
|
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| F
|
83.19
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83.19
|
0
|
|
|
| WD
|
String Module Error: Target string is empty ! 
|
|
|
|
| input
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C: 28.44, K: 301.59, F: 83.19
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| comment
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| style="text-align:left"|
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|
|
in
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calc from C
|
diff
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report
|
ref
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| C
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671
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—
|
—
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|
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| K
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944
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944
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0
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|
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| F
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1240
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1240
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0
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|
|
| WD
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String Module Error: Target string is empty !
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|
| input
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C: 671, K: 944, F: 1240
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| comment
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References
Thir references will appear in the airticle, but this list appears anerly on this page.
- ↑ Meija, Juris; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305.
- ↑ Dye, J. L. (1979). "Compounds of Alkali Metal Anions". Angewandte Chemie International Edition. 18 (8): 587–598. doi:10.1002/anie.197905871.
- ↑ "Magnetic susceptibility of the elements and inorganic compounds". Handbook of Chemistry and Physics (PDF) (87th ed.). CRC press. ISBN 0-8493-0487-3. Retrieved 26 September 2010.
- ↑ "NIST Radionuclide Half-Life Measurements". NIST. Retrieved 13 Mairch 2011.
