Cæsium

55
Cs
Gruppe
1
Periode
6
Blok
s
Protons
Electrons
Neutrons
55
55
78
General Properties
Atomnummer
55
Atommasse
132,9054519
Mass Number
133
Kategori
Alkalimetaller
Farve
Silver
Radioactive
Ja
From the Latin word caesius, sky blue
Krystalstruktur
Rumcentreret Kubisk
History
Robert Bunsen and Gustav Kirchhoff were the first to suggest finding cesium in 1860 by spectrum analysis.

They discovered cesium by its two blue emission lines in a sample of Dürkheim mineral water.

The pure metal was eventually isolated by the German chemist Carl Setterberg while working on his doctorate with Kekulé and Bunsen.
Elektroner i hver skal
2, 8, 18, 18, 8, 1
Elektronkonfiguration
[Xe] 6s1
Cs
Cesium was the first element discovered using a spectroscope
Physical Properties
Tilstandsform
Fast stof
Massefylde
1,873 g/cm3
Smeltepunkt
301,59 K | 28,44 °C | 83,19 °F
Kogepunkt
944,15 K | 671 °C | 1239,8 °F
Smeltevarme
2,09 kJ/mol
Fordampningsvarme
65 kJ/mol
Varmefylde
0,242 J/g·K
Abundance in Earth's crust
0,00019%
Abundance in Universe
8×10-8%
Cesium
Billede akkrediteringer: Wikimedia Commons (Dnn87)
Cesium metal sample from the Dennis s.k collection
CAS Number
7440-46-2
PubChem CID Number
5354618
Atomic Properties
Atomradius
265 pm
Kovalent radius
244 pm
Elektronegativitet
0,79 (Paulings skala)
Ionization Potential
3,8939 eV
Atomic Volume
71,07 cm3/mol
Varmeledningsevne
0,359 W/cm·K
Oxidationstrin
-1, 1
Applications
The radioactive isotope cesium-137 has a half-life of about 30 years and is used in medical applications, industrial gauges, and hydrology.

Cesium is also used in photoelectric cells and as a catalyst in the hydrogenation of organic compounds.

Cesium vapor thermionic generators are low-power devices that convert heat energy to electrical energy.
Cesium compounds are considered to be mildly toxic
Isotoper
Stable Isotopes
133Cs
Unstable Isotopes
112Cs, 113Cs, 114Cs, 115Cs, 116Cs, 117Cs, 118Cs, 119Cs, 120Cs, 121Cs, 122Cs, 123Cs, 124Cs, 125Cs, 126Cs, 127Cs, 128Cs, 129Cs, 130Cs, 131Cs, 132Cs, 134Cs, 135Cs, 136Cs, 137Cs, 138Cs, 139Cs, 140Cs, 141Cs, 142Cs, 143Cs, 144Cs, 145Cs, 146Cs, 147Cs, 148Cs, 149Cs, 150Cs, 151Cs