Rubidium
chemical element with symbol Rb and atomic number 37 / From Wikipedia, the free encyclopedia
Rubidium is chemical element 37 on the periodic table. Its symbol is Rb. Its atomic mass is 85.47. It has 37 protons and 37 electrons. It is a soft silver colored metal. It was first discovered in 1861 by Robert Bunsen and Gustav Kirchoff in Heidelberg, Germany.[1]