Atomic number:37

Group numbers:1

Period:5

Electronic configuration:[Kr] 5s¹

Formal oxidation number:+1

Electronegativities:0.82

Atomic radius / pm:247.5

Relative atomic mass:85.4678 ± 0.0003

 

Rubidium was discovered by Robert Wilhelm Bunsen and Gustav Robert Kirchhoff (DE) in 1861. The origin of the name comes from the Latin word rubidius meaning dark red or deepest red. It is a soft, silvery-white, highly reactive metal that ignites in air and reacts violently with water or oxidants. Rubidium occurs abundantly, but so widespread that production is limited. It is usually obtained from lithium production. It is used in photocells, cathode-ray and vacuum tubes, and as a catalyst.

Density / g dm^-3:1532 (293 K)

 1475 (m.p.)

Molar volume / cm³mol^-1:55.79 (293 K)

 57.94 (m.p.)

Electrical resistivity / μΩcm:12.5 (20 °C)

Thermal conductivity / W m^-1K^-1:52.8

Melting point / °C:39.31

Boiling point / °C:688

Heat of fusion / kJ mol^-1:2.2

Heat of vaporization / kJ mol^-1:75.7

Heat of atomization / kJ mol^-1:82.17

1st ionization energy / kJ mol^-1:403.03

2nd ionization energy / kJ mol^-1:2632.62

3rd ionization energy / kJ mol^-1:3859.44

in the atmosphere / ppm:-

in the Earth's crust / ppm:32

in the oceans / ppm:0.12