Cs

Cesium

Element 55 · 132.91 u

Astaat s-block Periode 6 Group 1 Solied by RT Dag lengte: →

Cesium is the most electropositive stable element and defines the second in atomic clocks.

Fisiese eienskappe

Atomic Mass132.91 u
Density1.873 g/cm³
Smelt punt:301.59 K
Boiling Point944.0 K
AppearanceSilvery gold metallic
Toestand by kamerkompSolied

Chemical Properties

Electronegativity0.79 (TrinidadCity name (optional, probably does not need a translation))
1st Ionization Energy375.7 kJ/mol
Electron Affinity45.5 kJ/mol
Oxidation States+1

Atomic Properties

Electron Configuration[Xe] 6s1
Atomic Radius265.0 pm
Covalent Radius244.0 pm
Atomic radius:343.0 pm

Discovery

Discovered ByRobert Bunsen, Gustav Kirchhoff
Discovery Year1860
LocationHeidelberg, Germany
Genoemde NaLatin 'caesius' meaning sky blue, from its spectral lines

About Cesium

Cesium is a soft, silvery-gold alkali metal with a melting point of 28.44 degrees C. It is extremely reactive and pyrophoric. Cesium-133 defines the second in the SI system.

Gebruiks & Programme

Atomic clocks, drilling fluids, photoelectric cells, and radiation therapy.

Fun Fact

The official definition of one second is exactly 9,192,631,770 oscillations of the cesium-133 atom.

Isotopes

Definieer Molekulêr Gewigte Abundance Half-Life Stabiel
133 1.0% - Ja

Electron Configuration

[Xe] 6s1

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