Cesium (noun)

A metallic element with the atomic number 55 and symbol Cs, that is highly reactive and used in atomic clocks and other electronic devices.

Origin:

The word cesium is derived from the latin word caesius, meaning "sky blue". it was named after the sky-blue spectral lines of cs that are characteristic of the element.

Examples:

1. Cesium is a rare element that is found in small amounts in the earth's crust.
2. Cesium is used in atomic clocks to keep accurate time.
3. Cesium is a highly reactive element that can ignite spontaneously in air.
4. Cesium is used in the production of various electronic devices.
5. Cesium is a key component in the production of certain types of glass.