Discovered By: Robert Wilhelm Bunsen, Gustav Kirchhoff
Discovery year: 1861

The following table showing some properties of Rubidium(Rb):

Table Example
Atomic number 37
Group 1
Period 5
Block s
Electrons 37
Protons 37
Neutrons 48
Atomic weight 85.4678
Oxidation states +1
Ionic states Rb^+


Table Example
Electrons per shell K2 L8 M18 N8 O1
Electron configuration 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^6 5s^1
Atomic radius 265 pm
Covalent radius 220 pm
Boiling point 688°C
Melting point 39.31°C
Phase Solid
Fusion heat 2.19 kJ.mol^-1
vaporization heat 72 kJ.mol^-1
Color Silver


Table Example
Brinell hardness 0.216 MPa
Bulk modulus 2.5 GPa
Density 1532 kg.m^-3
Liquid density 1460 kg.m^-3
Mohs hardness 0.3
Molar volume 5.579*10^-5 m^3.mol^-1
Sound speed 1300 m.s^-1
Thermal conductivity 58 W.m^-1.K^-1
Young's modulus 2.4 GPa
Electrical conductivity 8.3*10^6 S.m^-1


Table Example
Electric type Conductor
Magnetic type Paramagnetic
Resistivity 1.2*10^-7 Ohm.m
Electronegativity 0.82
Valence 1
Radioactive No
Neutron cross section 0.38 barn
Electron affinity 46.9 kJ.mol^-1
First ionization energy 403 kJ.mol^-1
Volume magnetic susceptibility 3.98*10^-6