Electronic data		Thermal data		Steric data
Shells: 2,8,18,8,1 Orbitals: [Kr] 5s1 Electronegativity: 0.9, 0.8 1. Ionization potential: 4.1771 eV 2. Ionization potential: 27.28 eV 3. Ionization potential: 40.0 eV Oxidation states: 1 Electrical conductivity: 0.0779 10^6		Melting point: 38.89 °C Boiling point: 686 °C Specific heat: 0.363 J/gK Heat of fusion: 2.192 kJ/mol Heat of vaporization: 72.216 kJ/mol Thermal conductivity: 0.582 W/cmK		Atomic radius: 2.98 Å Ionic radius: 1.61 Å () Covalent radius: 2.16 Å Atomic volume: 55.9 cm³/mol Density (293 K): 1.53 g/cm³ Crystal structure: Cubic: Body centered

Legend     Pocket calculator

Nuclide	Abundance [%]	Mass	Spin	Halflife	Decay mode	Decay tree
81Rb	0	81	3/2	4.57h	EC,+	View
82Rb	0	82	1	1.258m	+,EC	View
83Rb	0	83	5/2	86.2d	EC,EC	View
84Rb	0	83.914	2	32.9d	EC,+,-	View
85Rb	72.15	84.9118	5/2	--	stable	--
85Rbm	0	85	0	>1µs	IT	View
86Rb	0	85.911	2	18.65d	-,EC	View
87Rb	27.85	86.9092	3/2	4.8E10y	-	View
88Rb	0	88	2	17.7m	-	View
89Rb	0	89	3/2	15.44m	-	View
90Rb	0	90	1	2.6m	-	View
90Rbm	0	90	4	4.3m	-,IT	View

Legend

Name origin:	Latin: rubidus (deep red); the color its salts impart to flames
Description:	Soft, silvery-white, highly reactive metal.
Discovered by:	R. Bunsen, G. Kirchoff
Year:	1861
Place:	Germany
Sources:	Occurs abundantly, but so widespread that production is limited. Usually obtained from lithium production.
Use(s):	Used as a catalyst, photocells, and vacuum and cathode-ray tubes.