Caesium was discovered by German chemists, Robert Wilhelm Bunsen and Gustav Robert Kirchhoff, in 1860 by the newly developed method of flame spectroscopy.
Name: Caesium Symbol: Cs Atomic number: 55 Atomic weight: 132.91 State: solid Group, period, block: 1, 6, s Color: silvery gold Classification: alkali metal Electron configuration: 6s1
Density: 1.93 g/cm-3 Melting point: 301.59 K, 28.44 °C, 83.19 °F Boiling point: 944 K, 671 °C, 1240 °F
Oxidation states: 1 Electronegativity: 0.79 (Pauling scale) Ionization energies: 1st: 375.7 kJ·mol-1 Covalent radius: 244±11 pm Van der Waals radius: 343 pm
There is one naturally occurring isotope of caesium exists, 133Cs.