Cesium (Cs)
Cesium is the most electropositive stable element. Atomic clocks based on cesium are used to define the second.
Properties of Cesium
- Atomic number
- 55
- Category
- Alkali Metal
- Atomic mass
- 132.91 u
- Electron configuration
- [Xe] 6s¹
- Melting point
- 301.7 K (28.55 °C)
- Boiling point
- 944 K (670.85 °C)
- Density
- 1.873 g/cm³
- Electronegativity (Pauling)
- 0.79
- Appearance
- Silvery-gold metal
- Discovered by
- Robert Bunsen (1860)
Facts about Cesium
- Cesium atomic clocks are so accurate they won't lose a second in 300 million years!
- Cesium is one of only three metals that are gold-colored (along with gold and copper)!
- Cesium explodes violently in water — even more dramatically than sodium or potassium!
- Cesium melts at just 28°C — it would melt in your hand!