Cesiu

55
Cs
Grupă
1
Perioadă
6
Bloc
s
Protoni
Electroni
Neutroni
55
55
78
Proprietăți Generale
Număr atomic
55
Masă atomică
132,9054519
Numar de masa
133
Categorie
Metale alcaline
Culoare
Argint
Radioactive
Da
Din cuvântul latin caesius, cer albastru
Structură cristalină
Corp Centrat Cubic
Istoric
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.
Electroni pe nivelul de energie
2, 8, 18, 18, 8, 1
Configurație electronică
[Xe] 6s1
Cs
Cesium was the first element discovered using a spectroscope
Proprietăți Fizice
Fază
Solid
Densitate
1,873 g/cm3
Punct de topire
301,59 K | 28,44 °C | 83,19 °F
Punct de fierbere
944,15 K | 671 °C | 1239,8 °F
Energie de fuziune
2,09 kJ/mol
Energie de evaporare
65 kJ/mol
Căldură specifică
0,242 J/g·K
Abundența în scoarța Pământului
0,00019%
Abundența în Univers
8×10-8%
Cesium
Credite imagine: Wikimedia Commons (Dnn87)
Cesium metal sample from the Dennis s.k collection
CAS Number
7440-46-2
PubChem CID Number
5354618
Proprietăți Atomice
Rază atomică
265 pm
Rază de covalență
244 pm
Electronegativitate
0,79 (Scara lui Pauling)
Potențial de ionizare
3,8939 eV
Volum molar
71,07 cm3/mol
Conductivitate termică
0,359 W/cm·K
Număr de oxidare
-1, 1
Aplicații
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
Izotopi
Izotopi stabili
133Cs
Izotopi instabili
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