Appearance and Characteristics
Harmful effects:
Cesium must be kept under an inert liquid/gas or in a vacuum to protect it from air and water. Cesium compounds are considered to be mildly toxic.
Characteristics:
Cesium is silvery-gold, soft, ductile alkali metal. It is liquid in a warm room, melting at 28.4 oC (83.1 oF). Cesium is one of the few metals that is liquid near room temperature. The others are gallium, francium and mercury. Cesium is an extremely reactive metal and the most alkaline of the elements. It reacts explosively upon contact with water producing cesium hydroxide (CsOH), an extremely strong base that can rapidly corrode glass.
Uses of Cesium
Cesium is used in atomic clocks, which are incredibly accurate. NIST-F1, America’s primary time and frequency standard, is a cesium fountain atomic clock developed at the NIST laboratories in Boulder, Colorado. NIST-F1 contributes to the international group of atomic clocks that define Coordinated Universal Time (UTC), the official world time. As scientists continue to improve its technology, uncertainty in NIST-F1′s measurement of time is continually improving. Currently it neither gains nor loses as much a second in more than 60 million years – but see strontium.
Cesium is also used in photoelectric cells and as a catalyst in the hydrogenation of organic compounds. The metal is used as a ‘getter’ in vacuum tubes.
Cesium hydroxide is used to etch silicon.