Answer:
Rubidium is used in vacuum tubes as a getter, a material that combines with and removes trace gases from vacuum tubes. It is also used in the manufacture of photocells and in special glasses. Since it is easily ionized, it might be used as a propellant in ion engines on spacecraft.
Symbol: Rb (37)
Atomic Weight: 85.4678
Atomic Number: 37
Number of Stable Isotopes: 1 (View all isotope .