โ–ธโ–ธ
  • ๐Ÿ‡ฌ๐Ÿ‡ง Rubidium
  • ๐Ÿ‡จ๐Ÿ‡ณ ้Šฃ
  • ๐Ÿ‡ณ๐Ÿ‡ฑ Rubidium
  • ๐Ÿ‡ซ๐Ÿ‡ท Rubidium
  • ๐Ÿ‡ฉ๐Ÿ‡ช Rubidium
  • ๐Ÿ‡ฎ๐Ÿ‡ฑ ืจื•ื‘ื™ื“ื™ื•ื
  • ๐Ÿ‡ฎ๐Ÿ‡น Rubidio
  • ๐Ÿ‡ฏ๐Ÿ‡ต ใƒซใƒ“ใ‚ธใ‚ฆใƒ 
  • ๐Ÿ‡ต๐Ÿ‡น Rubídio
  • ๐Ÿ‡ท๐Ÿ‡บ ะ ัƒะฑะธะดะธะน
  • ๐Ÿ‡ช๐Ÿ‡ธ Rubidio
  • ๐Ÿ‡ธ๐Ÿ‡ช Rubidium

Rubidium: the essentials

Rubidium atoms have 37 electrons and the shell structure is 2.8.18.8.1. The ground state electronic configuration of neutral rubidium is [Kr].5s1 and the term symbol of rubidium is 2S1/2.

Rubidium: description  

Rubidium can be liquid at ambient temperature, but only on a hot day given that its melting point is about 40°C. It is a soft, silvery-white metallic element of the alkali metals group (Group 1). It is one of the most most electropositive and alkaline elements. It ignites spontaneously in air and reacts violently with water, setting fire to the liberated hydrogen. As so with all the other alkali metals, it forms amalgams with mercury. It alloys with gold, caesium, sodium, and potassium. It colours a flame yellowish-violet.

Science and Ink cartoon for rubidium
Cartoon by Nick D Kim ([Science and Ink], used by permission).

rubidium
Image adapted with permission from Prof James Marshall's (U. North Texas, USA) Walking Tour of the elements CD.

Rubidium: physical properties

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Rubidium: heat properties

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Rubidium: atom sizes

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Rubidium: electronegativities

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Rubidium: orbital properties

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Rubidium: abundances

More geological data...

Rubidium: crystal structure

Rb crystal structure
The solid state structure of rubidium is: bcc (body-centred cubic).

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Rubidium: biological data

Rubidium has no biological role but is said to stimulate the metabolism. It can accumulate ahead of potassium in muscle.

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Rubidium: uses

Uses...

Rubidium: reactions

Reactions of rubidium as the element with air, water, halogens, acids, and bases where known.

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Rubidium: binary compounds

Binary compounds with halogens (known as halides), oxygen (known as oxides), hydrogen (known as hydrides), and other compounds of rubidium where known.

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Rubidium: compound properties

Bond strengths; lattice energies of rubidium halides, hydrides, oxides (where known); and reduction potentials where known.

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Rubidium: history

Rubidium was discovered by Robert Bunsen, Gustav Kirchhoff in 1861 at Germany. Origin of name: from the Latin word "rubidius" meaning "dark red" or "deepest red".

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Rubidium: isotopes

Isotope abundances of rubidium
Isotope abundances of rubidium with the most intense signal set to 100%.

More isotope and NMR data...

Rubidium: isolation

Isolation: rubidium would not normally be made in the laboratory as it is available commercially. All syntheses require an electrolytic step as it is so difficult to add an electron to the poorly electronegative rubidium ion Rb+.

Rubidium is not made by the same method as sodium as might have been expected. This is because the rubidium metal, once formed by electrolysis of liquid rubidium chloride (RbCl), is too soluble in the molten salt.

cathode: Rb+(l) + e- → Rb (l)

anode: Cl-(l) → 1/2Cl2 (g) + e-

Instead, it is made by the reaction of metallic sodium with hot molten rubidium chloride.

Na + RbCl ⇌ Rb + NaCl

This is an equilibrium reaction and under these conditions the rubidium is highly volatile and removed from the system in a form relatively free from sodium impurities, allowing the reaction to proceed.