Rubidium

**Definition:** An element that is an alkali metal. It has an atomic symbol Rb, atomic number 37, and atomic weight 85.47. It is used as a chemical reagent and in the manufacture of photoelectric cells.

**Tree numbers:** - D01.268.549.650 - D01.268.556.800 - D01.552.528.759 - D01.552.544.800