

It is possible that, after the salt Cs +F − has formed, the Cs + ion, which has the same electronic structure as elemental xenon, can like xenon be oxidised further by fluorine and form traces of a higher fluoride such as CsF 3, analogous to XeF 2. There is an account that caesium, reacting with fluorine, takes up more fluorine than it stoichometrically should. CsOH is often stated to be the "strongest base" (after FrOH), but in fact many compounds such as n-butyllithium and sodium amide are stronger. Caesium reacts explosively in cold water and also reacts with ice at temperatures above −116☌.Ĭaesium hydroxide (CsOH) is a very strong base and will rapidly etch the surface of glass. (Technically, francium is the least common alkali metal, but since it is highly radioactive with an estimated 340 to 550 grams in the entire earth at one time, its abundance can be considered zero in practical terms.)Īlong with gallium, francium, and mercury, caesium is among the only metals that are liquid at or near room temperature.

Caesium is the least abundant of the five non-radioactive alkali metals. Caesium is also the most electropositive and most alkaline of the stable chemical elements and has the second lowest ionization potential ( francium being the lowest). This metal is silvery gold in colour and is both soft and ductile. The electromagnetic spectrum of caesium has two bright lines in the blue part of the spectrum along with several other lines in the red, yellow, and green. The variant spelling cesium is sometimes used, especially in North American English, but caesium is the spelling used by the IUPAC, although since 1993 it has recognized cesium as a variant as well. This element is most notably used in atomic clocks. It is a soft silvery-gold alkali metal with a melting point of 28 ☌ (83 ☏) which makes it one of the metals that are liquid at or near room temperature along with rubidium (39☌), francium (27 ☌), mercury (-39 ☌), and gallium (30 ☌). Caesium (also spelled cesium, IPA: /ˈsiːziəm/) is a chemical element in the periodic table that has the symbol Cs and atomic number 55.
