CAS Number7440-74-6
PubChem CID5359967
Atomic Radius167
Atomic Volume15.7
Atomic Weight114.818
Boiling Point2,072
Bulk Modulus
CategoryPost-transition metals
Crystal StructureCentered Tetragonal
Covalent Radius142
Electrical Resistivity
Electron Configuration[Kr] 4d10 5s2 5p1
Electrons per shell2, 8, 18, 18, 3
Heat of Fusion3.26
Heat of Vaporization230
Ionization Potential5.786
Magnetic Ordering
Magnetic Susceptibility
Mass Number49
Melting Point156.6
Atomic Number115
Oxidation States1, 2, 3
Poisson Ratio
Shear Modulus
Specific Heat Capacity0.233
Thermal Conductivity0.816
Van der Waals radius
Young's Modulus
Abundance in Earth's crust0.000016%
Abundance in Universe3×10-8%
In Indium 49 114.818 13 5 p 49 156.6 2080.0 [Kr] 4d10 5s2 5p1 2 8 18 18 3 7.31 0.000016% Silver Tetragonal 1.8 1.656 {"1":"558.3","2":"1820.7","3":"2704","4":"5210"} 558 28.9 144 3 1.66 15.7 3.26 226.35 0.233 81.6 0 Solid, Diamagnetic, Conductor, Metal, Stable, Natural, PoorMetal IN-di-em Rare, very soft, silver-white metal Used to coat high speed bearings and as an alloy that lowers the melting point of other metals. Relativly small amounts are used in dental items and in electronic semiconductors. Found in certain zinc ores. 4opHafNmgCw Indium
German chemists Robert Bunsen and Gustav Kirchhoff discovered rubidium in 1861 by the newly developed method of flame spectroscopy.

The separation of the metal was tried by Bunsen, but he never got samples with more than 18% of Rubidium.

The separation of the metal was only accomplished by George de Hevesy, through the hydrolysis of melted rubidium hydroxide. From the Latin word rubidus, deepest red 49 1863 Ferdinand Reich, Hieronymus Theodor Richter Germany Named after the indigo line in its atomic spectrum

Isotopes of Rubidium

Standard Atomic Weight


Stable Isotopes

113In 115In

Unstable Isotopes

97In 98In 99In 100In 101In 102In 103In 104In 105In 106In 107In 108In 109In 110In 111In 112In 114In 116In 117In 118In 119In 120In 121In 122In 123In 124In 125In 126In 127In 128In 129In 130In 131In 132In 133In 134In 135In

Rubidium is not known to be toxic
Rubidium burns with a reddish-violet flame color
Rubidium is used as a getter in vacuum tubes and as a photocell component.

Rubidium compounds are sometimes used in fireworks to give them a purple color.

Rubidium salts are used in glasses and ceramics.

Rubidium-87 is slightly radioactive and has been used extensively in dating rocks.