Cesium
Cesium General
| Name:Cesium | Symbol:Cs |
| Type: Alkali Metal | Atomic weight:132.9055 |
| Density @ 293 K:1.873 g/cm3 | Atomic volume:71.07 cm3/mol |
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Discovered:
Cesium was discovered by Robert Bunsen and Gustav Kirchhoff in 1860, when they analyzed the spectrum of mineral water. Cesium was the first element discovered using a spectroscope. The origin of the name comes from the Latin word 'caesius', meaning sky blue. The Latin spelling is still reflected in British English where cesium is spelt caesium. |
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Cesium States
| State (s, l, g):solid | |
| Melting point:301.6 K (28.4 °C) | Boiling point:943.2 K (670 °C) |
Cesium Energies
| Specific heat capacity:0.24 J g-1 K-1 | Heat of atomization:76 kJ mol-1 |
| Heat of fusion:2.092 kJ mol-1 | Heat of vaporization :67.740 kJ mol-1 |
| 1st ionization energy: 375.7 kJ mol-1 | 2nd ionization energy: 2234.3 kJ mol-1 |
| 3rd ionization energy:3400 kJ mol-1 | Electron affinity:45.506 kJ mol-1 |
Cesium Oxidation & Electrons
| Shells:2,8,18,18,8,1 | Electron configuration: [Xe] 6s1 |
| Minimum oxidation number:0 | Maximum oxidation number:3 |
| Min. common oxidation no.:0 | Max. common oxidation no.:3 |
| Electronegativity (Pauling Scale): 0.79 | Polarizability volume:59.6 Å3 |
Cesium Appearance & Characteristics
| Structure:bcc: body-centered cubic | Color:yellow/silvery |
| Hardness:0.2 mohs | |
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Harmful effects:
Cesium must be kept under an inert liquid/gas or in a vacuum to protect it from air and water. Cesium compounds are considered to be mildy toxic. |
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Characteristics:
Cesium is silvery-gold, soft, ductile alkali metal. It is liquid in a warm room, melting at 28.4 °C(83.1 °F). Uses: Cesium is used in atomic clocks, which are incredibly accurate. NIST-F1, America's primary time and frequency standard, is a cesium fountain atomic clock developed at the NIST laboratories in Boulder, Colorado. NIST-F1 contributes to the international group of atomic clocks that define Coordinated Universal Time (UTC), the official world time. As scientists continue to improve its technology, uncertainty in NIST-F1's measurement of time is continually improving. Currently it neither gains nor loses as much a second in more than 60 million years - but see strontium. Cesium is also used in photoelectric cells and as a catalyst in the hydrogenation of organic compounds. The metal is used as a 'getter' in vacuum tubes. |
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Cesium Reactions
| Reaction with air:vigorous, ⇒ Cs2O | Reaction with 6 M HCl:vigorous, ⇒ H2, CsCl |
| Reaction with 15 M HNO3:vigorous, ⇒ CsNO3 | Reaction with 6 M NaOH:vigorous, ⇒ H2, CsOH |
Cesium Compounds
| Oxide(s):Cs2O, Cs2, Cs2O2 | Chloride(s):CsCl |
| Hydride(s):CsH |
Cesium Radius
| Atomic radius:260 pm | Ionic radius (1+ ion):181 pm |
| Ionic radius (2+ ion): pm | Ionic radius (3+ ion): pm |
| Ionic radius (2- ion): pm | Ionic radius (1- ion): pm |
Cesium Conductivity
| Thermal conductivity:35.9 W m-1 K-1 | Electrical conductivity:5.3 x 106 S m-1 |
Cesium Abundance & Isotopes
| Abundance earth's crust:3 parts per million by weight, 0.5 parts per million by moles | |
| Abundance solar system: 8 parts per billion by weight, 70 parts per trillion by moles | |
| Cost, pure:$1100 per 100g | |
| Cost, bulk:$ per 100g | |
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Source:
Cesium is found in the minerals pollucite and lepidolite. Commercially, most cesium is produced as a byproduct of the production of lithium metal. More than two-thirds of the world's reserves of Cesium - 110,000 tonnes - are found at Bernic Lake, Manitoba, Canada. |
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Isotopes:
Cesium has 36 isotopes whose half-lives are known, with mass numbers 112 to 148. Of these, one is stable: 133Cs. |
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Cesium Other
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Other:
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