Caesium

Caesium or cesium (pronounced /ˈsiːziəm/, SEE-zee-əm) is the chemical element with the symbol Cs and atomic number 55. It is a soft, silvery-gold alkali metal with a melting point of 28 °C (83 °F), which makes it one of only five metals that are liquid at or near room temperature. Caesium is most notably used in atomic clocks. Caesium is the international spelling standardized by the IUPAC, but in the United States it is more commonly spelled as ... more

Caesium or cesium (pronounced /ˈsiːziəm/, SEE-zee-əm) is the chemical element with the symbol Cs and atomic number 55. It is a soft, silvery-gold alkali metal with a melting point of 28 °C (83 °F), which makes it one of only five metals that are liquid at or near room temperature. Caesium is most notably used in atomic clocks. Caesium is the international spelling standardized by the IUPAC, but in the United States it is more commonly spelled as cesium. The emission spectrum of caesium has two bright lines in the blue area of the spectrum along with several other lines in the red, yellow, and green areas. This metal is silvery gold in color and is both soft and ductile. Caesium has the lowest ionization potential of the chemical elements. Caesium is the least abundant of the five non-radioactive alkali metals. (Francium is the least common alkali metal but it has no stable isotopes.). Caesium, gallium, francium, rubidium, and mercury are the only pure metals liquid at or near room... less