55 Cs 132.905
Cesium
alkali metal
Properties
- Atomic number
- 55
- Atomic mass
- 132.905 u
- Category
- alkali metal
- Group
- 1
- Period
- 6
- Block
- s-block
- State (room temp)
- Solid
- Outer-shell electrons
- 1
- Electronegativity
- 0.79 (Pauling)
- Density
- 1.93 g/cm³
- Melting point
- 28.55 °C
- Boiling point
- 670.85 °C
Electron configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s¹
Noble-gas shorthand: [Xe] 6s¹
Electrons per shell: 2, 8, 18, 18, 8, 1 — that's 1 in the outermost shell.
About Cesium
Caesium or cesium is a chemical element with symbol Cs and atomic number 55. It is a soft, silvery-gold alkali metal with a melting point of 28 °C (82 °F), which makes it one of only five elemental metals that are liquid at or near room temperature. Caesium is an alkali metal and has physical and chemical properties similar to those of rubidium and potassium.
- Discovered by Robert Bunsen
- Appearance: silvery gold
Position in the periodic table
Data compiled from Wikipedia, PubChem, and IUPAC. Source.