Wikijunior:The Elements/Cesium

Shows the position of Cesium on the periodic chart.

Cesium's symbol on the Periodic Table

Cesium metal

What does it look, feel, taste, or smell like?

Cesium is a silvery-gold color. It is a soft alkali metal, with a very low melting point — 28C, which is below human body temperature (37C).

How was it discovered?

It was discovered in 1860 by two German chemists, Robert Bunsen and Gustav Kirchhoff. They discovered it in mineral water from a spa in Germany, using a spectroscope — which they had discovered the previous year.

Where did its name come from?

Did You Know?

• It is liquid at or near room temperature.
• It has been widely used in highly accurate atomic clocks.
• The largest application of cesium has been as cesium formate for drilling fluids

Bunsen and Kirchhoff named this element after the color of the light they observed from it with their spectroscope. The Latin word caesius means bluish-gray.

What are its uses?

Cesium plays a role in getting oil to run your car and power your home. It can be used in some forms of oil drilling, acting as a lubricant and maintaining pressure.

Cesium binds well with oxygen and other gases, so it is also helpful in making vacuum tubes in order to remove the remaining oxygen from the tubes.

When used as a coating on cathode tubes, it can increase the electric current.

Is it dangerous?

Cesium burns when it comes in contact with the air and vigorously explodes when exposed to water.