Cesium (Cs) — Element Properties, Uses & Facts
Overview
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.
Electron configuration
The electron configuration of Cesium is [Xe] 6s1, with electron shells of 2, 8, 18, 18, 8, 1.
Physical and chemical properties
Cesium is classified as a alkali metal. It has an atomic mass of 132.905 and exists as a solid at standard conditions, appearing as silvery gold.
Real-world uses of Cesium
Like other alkali metals, Cesium is highly reactive and is mainly studied and used in chemical research, battery technology, and specialized industrial compounds rather than in its pure metallic form.
Interesting facts about Cesium
- Cesium has the atomic number 55 and chemical symbol Cs.
- It belongs to period 6, group 1 of the periodic table.
- Cesium was discovered by Robert Bunsen.
Explore Cesium interactively
Want to compare Cesium with other elements or see it highlighted on the full table? Open the interactive periodic table and click on Cs to explore properties, trends, and neighboring elements. You can also test your knowledge with our periodic table quiz game.
What is Cesium used for?
Like other alkali metals, Cesium is highly reactive and is mainly studied and used in chemical research, battery technology, and specialized industrial compounds rather than in its pure metallic form.
What is the atomic number of Cesium?
The atomic number of Cesium is 55, meaning it has 55 protons in its nucleus.
What is the electron configuration of Cesium?
The electron configuration of Cesium is [Xe] 6s1.
Is Cesium a metal, nonmetal, or metalloid?
Cesium is classified as a alkali metal.