Menu
Other Resources

Compare Sodium vs Rubidium

Comparing Sodium (Na) and Rubidium (Rb). Atomic numbers 11 and 37 with atomic masses 22.99 u and 85.468 u, classified as alkali metal and alkali metal. Below: a side-by-side comparison of their physical, atomic, electron-configuration and historical properties, including density, melting and boiling points, ionization energies, oxidation states and discovery history.

vs
Na
Sodium
#11
Rb
Rubidium
#37

Periodic properties of the elements

SodiumRubidium
SymbolNaRb
Atomic number1137
Group11
Period35
Blockss
Element categoryAlkali MetalAlkali Metal

Physical properties

SodiumRubidium
Phase at STPSolidSolid
Density0.968 g/cm31.532 g/cm3
Atomic weight22.9898 u85.4678 u
Melting point370.944 K
97.794 °C
208.0292 °F		312.45 K
39.3 °C
102.74 °F
Boiling point1156.09 K
882.94 °C
1621.292 °F		961 K
687.85 °C
1270.13 °F

Atomic properties

SodiumRubidium
Electronegativity (Pauling Scale)0.930.82
Electron affinity52.867 kJ/mol46.884 kJ/mol
Oxidation states−1, +1
(a strongly basic oxide)		−1, +1
(a strongly basic oxide)
Ionization energies
  1. 495.8 kJ/mol
  2. 4562 kJ/mol
  3. 6910.3 kJ/mol
  4. 9543 kJ/mol
  5. 13354 kJ/mol
  6. 16613 kJ/mol
  7. 20117 kJ/mol
  8. 25496 kJ/mol
  9. 28932 kJ/mol
  10. 141362 kJ/mol
  11. 159076 kJ/mol
  1. 403 kJ/mol
  2. 2633 kJ/mol
  3. 3860 kJ/mol
  4. 5080 kJ/mol
  5. 6850 kJ/mol
  6. 8140 kJ/mol
  7. 9570 kJ/mol
  8. 13120 kJ/mol
  9. 14500 kJ/mol
  10. 26740 kJ/mol

Electron configuration

SodiumRubidium
Shorthand configuration[Ne] 3s1 [Kr] 5s1
Full configuration1s2 2s2 2p6 3s1 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 5s1
Electrons per shell2, 8, 12, 8, 18, 8, 1

History

SodiumRubidium
DiscoveryHumphry Davy (1807)Robert Bunsen, Gustav Kirchhoff (1861)
First isolationHumphry Davy (1807)Robert Bunsen (1863)
Compare Sodium with
Compare Rubidium with