Cesium is located on the sixth row of the first column in the periodic table of elements. Its appearance is silvery gold with a melting point of 28 degrees Celsius. Cesium is the most reactive alkali metal. It is can also be considered to be one of the most electropositive elements in the periodic table. It is stored in sealed ampules filled either with Argon or a vacuum.Cesium is a very soft metal that can be cut with a butter knife. Cesium's main isotope is Cesium 133. However, many more have been produced artificially. 

One of Cesium's most notable uses is in atomic clocks. Microwave radiation is used to excite atoms of Cesium 133 between 2 energy states at an astonishing 9,192,631,770 times a second. That is is why atomic clocks are some of the most accurate clocks in existence. Cesium is also used in drilling fluids.