Rubidium is a chemical element with symbol Rb and atomic number 37. Rubidium is a soft, silvery-white metallic element of the alkali metal group, with a standard atomic weight of 85.4678.

Atomic Weight:  85.4678
Density:        1.532 g/cm3
Melting Point:  39.31 °C
Boiling Point:  688 °C