Atomic Number of Caesium

Caesium Atomic Number

Atomic Number of Caesium is 55.

Chemical symbol for Caesium is Cs. Number of protons in Caesium is 55. Atomic weight of Caesium is 132.905452 u or g/mol. Melting point of Caesium is 28,4 °C and its the boiling point is 690 °C.

» Boiling Point » Melting Point » Abundant » State at STP » Discovery Year

About Caesium

Caesium is a soft metal of yellowish color, which is very highly reactive and can explode in water. The name of this chemical element is derived from a Latin word meaning blue flames which can be seen when this element burns. This element can be found in minerals and is stored in oil as it is very highly reactive. Caesium has no biological importance and in its pure form is not toxic or poisonous. The most common use of this element is producing so called Caesium clock, which is an atomic clock with extremely high precision. Such clocks are used for GPR connections and mobile networks. Other applications of caesium and its compounds include optical glass producing, producing drilling fluids, as well as being used as a catalyst in chemical industry.

Uses of Caesium

Caesium (Cs), also known as Cesium, is used in photoelectric cells, vacuum tubes, scintillation counters, spectrophotometers, atomic clocks (caesium clocks), and photomultiplier tubes. It can be also used in thermionic power converters. In addition, Caesium is employed as an industrial gamma-ray source. Caesium carbonate, a compound with the formula Cs2CO3, is used in organic synthesis as well as in energy conversion. Caesium oxide, consists of caesium and oxygen, is exploited in devices like vacuum photodiodes and TV camera tubes. Caesium sulfate, another compound with the formula Cs2SO4, is employed for preparing dense aqueous solutions for use in isopycnic centrifugation.

Compounds with Caesium

Properties of Caesium Element

Atomic Number (Z)55
Atomic SymbolCs
Atomic Weight132.905452 u
Density1.873 g/cm3
Melting Point (K)301.59 K
Melting Point (℃)28,4 °C
Boiling Point (K)944 K
Boiling Point (℃)690 °C
Heat Capacity0.242 J/g · K
Abundance3 mg/kg
State at STPSolid
DescriptionAlkali metal
Electronegativity (Pauling) χ0.79
Ionization Energy (eV)3.8939
Atomic Radius260pm
Covalent Radius225pm
Valence Electrons1
Year of Discovery1860
DiscovererKirchhoff and Bunsen

What is the Boiling Point of Caesium?

Caesium boiling point is 690 °C. Boiling point of Caesium in Kelvin is 944 K.

What is the Melting Point of Caesium?

Caesium melting point is 28,4 °C. Melting point of Caesium in Kelvin is 301.59 K.

How Abundant is Caesium?

Abundant value of Caesium is 3 mg/kg.

What is the State of Caesium at Standard Temperature and Pressure (STP)?

State of Caesium is Solid at standard temperature and pressure at 0℃ and one atmosphere pressure.

When was Caesium Discovered?

Caesium was discovered in 1860.