55
Cs
Cesium
Alkali metal period 6 group 1 s-block discovered: 1860
As a chemical element
Properties of the atom — they do not depend on what substance it is part of.
- Atomic number
- 55
- Atomic mass
- 132.9054520 a.m.u.
- Electron configuration
- [Xe]6s1
- Electronegativity
- 0.79 on the Pauling scale
- Atomic radius
- 343 pm
- Ionization energy
- 3.894 eV
- Electron affinity
- 0.472 eV
- Oxidation states
- +1
As a simple substance
Properties of the substance these atoms form under ordinary conditions.
- State at 25 °C
- Solid
- Melting point
- 301.59 K (28,44 °C)
- Boiling point
- 944 K (670,85 °C)
- Density
- 1.93 g/cm³