Cesium is a chemical element with the symbol Cs and atomic number 55. It is a soft, silvery-golden alkali metal that is highly reactive and has a low melting point. Cesium is known for its use in atomic clocks, which are extremely precise timekeeping devices that rely on the vibrations of cesium atoms to measure time. It is also used in various applications such as in photoelectric cells and for oil well drilling. Cesium is found naturally in small amounts in minerals such as pollucite and lepidolite.
