- Basic Facts -

>Picture of elemental Cesium


          Cesium was discovered by Gustav Kirchoff and Robert  Bunsen of Germany in 1860, however, it was first isolated by Carl Sefferburg in 1881.  Kirchoff and Robert named it Cesium because of the two bright blue lines that are characteristic of its spectrum.

Physical Properties:

- Melting Point- 28.4C

- Boiling Point- 669.3C

Cesium liquefies in a warm room; mercury and gallium are the only other metals with this property●

- Symbol- Cs

- Atomic Weight- 132.905

- Atomic Number- 55

>Atomic Structure


>Crystal Structures



Common Compounds:

- Cesium reacts readily with oxygen.

- it reacts explosively with water to form cesium hydroxide, the strongest base known.

-  reacts with ice at temperatures above -116C.

- Cesium reacts with the halogens to form a fluoride, chloride, bromide, and iodide. It also forms a sulfate, carbonate, nitrate, and cyanide.


- While in compounds with other elements Cesium is used in the production of glass and ceramics.  It is also used in antishock agents in conjunction with drugs containing arsenic.

- Cesium-137 (an isotope of Cesium), is created in the fallout of nuclear explosions.  This same isotope is used in the treatment of Cancer.

- Cesium is found in the mineral pollux (or pollucite) that is found in Maine and South Dakota

- Cesium is used as an ion propellant for rockets because its looses electrons readily and because its ions are heavy

- it removes traces of air in vaccum tubes

Characteristics:  soft, light, silvery white metal  


How Cool!!!!!

●  The National Institute of Standards and Technology (NIST) has created a "Cesium Fountain Atomic Clock" called NIST-F1.  It is the nation's primary time and frequency standard.  It was developed in the NIST laboratories in Boulder, Colorado.  This clock complies with others throughout the world to create the Coordinate Universal Time (UTC) - the official world time.

>what the clock looked like in 1955

>what it looks like today!

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