what letters are used to represent it?
Rb
Introduction
Rubidium is the chemical element with the symbol Rb and atomic number 37
where is rubidium found on the periodic table It is the 37th element.
Rb Rb Rb
Rubidium Rubidium Rubidium
Introduction Introduction Introduction
Rubidium is the chemical element with the symbol Rb and atomic number 37.  Rubidium is the chemical element with the symbol Rb  Rubidium is the chemical element with the symbol Rb and atomic number 37.
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Rubidium [SEP] Introduction
Rubidium is the chemical element with the symbol Rb and atomic number 37. Rubidium is a very soft, silvery-white metal in the alkali metal group. Rubidium metal shares similarities to potassium metal and caesium metal in physical appearance, softness and conductivity. Rubidium cannot be stored under atmospheric oxygen, as a highly exothermic reaction will ensue, sometimes even resulting in the metal catching fire. Rubidium is the first alkali metal in the group to have a density higher than water, so it sinks, unlike the metals above it in the group. Rubidium has a standard atomic weight of 85.4678. On Earth, natural rubidium comprises two isotopes: 72% is a stable isotope Rb, and 28% is slightly radioactive Rb, with a half-life of 49 billion years—more than three times as long as the estimated age of the universe.