Symbol Cs
Atomic Number 55
Atomic Mass 132.9054 g.mol -1
Discovered by Gustav Kirchhoff and Robert Bunsen in 1860

Chemical Properties of Cesium

Group 1 Melting point 28.5°C, 83.3°F, 301.7 K
Period 6 Boiling point 671°C, 1240°F, 944 K
Block s Density (g cm−3) 1.873
Atomic number 55 Relative atomic mass 132.905
State at 20°C Solid Key isotopes 133Cs
Electron configuration [Xe] 6s1 CAS number 7440-46-2

What is Cesium?

  • Cesium (Cs) is a chemical element in the periodic table with atomic number 55 discovered by Fustov Kirchhoff and Robert Bunsen in the year 1860.

  • The name is derived from a Latin word Caesius which means sky blue, as it burns with a blue flame.

Uses of Cesium

  • Cesium formate-based drilling fluids are extensively used in extractive oil industry.

  • It is used in thermionic generators which convert heat energy into electrical energy.

  • As the density of cesium is very high, cesium chloride, cesium sulphate are widely used in molecular biology.

  • Cesium is used in manufacturing optical glasses and other optical instruments. It is used to remove oxygen from light bulbs and vacuum tubes.

  • A special application of cesium is that it is used in the manufacturing of most accurate atomic clock. It is also called as cesium clock.

Properties of Cesium

  • It is a soft, silvery-gold alkali element that is quickly attacked by air and reacts explosively with water.

  • It is a very rare element and estimated that only 3 parts per million are available in the Earth’s Crust.

  • It is found in minerals like pollucite and lepidolite. It occurs in environment mainly due to erosion and withering of rocks.

Certain Facts About Cesium

  • Cesium has no biological importance and is not harmful to life.

  • When contact with radioactive cesium occurs, which hardly happens, a person may experience cell damage due to the harmful effects of radiation.