Name Rubidium
Symbol Rb
Atomic Number 37
Atomic Mass 85.4678 atomic mass units
Number of Protons 37
Number of Neutrons 48
Number of Electrons 37
Melting Point 38.89 C
Boiling Point 688.0 C
Density 1.532 grams per cubic centimeter
Normal Phase Solid
Family Alkali Metals
Period 5
Cost $25 per gram



Origin of Name From the Latin word "rubidius," which means dark red for its bright red spectroscopic lines
Date and Place of Discovery 1861 in Heidelberg, Germany
Discovered by Robert Wilhelm Bunsen and Gustav Kirchoff
Common Compounds
Interesting facts
  • It is the 16th most common element in the earth's crust.
  • It is found in North America, Rush and South Africa.
  • It can also be found in seawater and in mineral springs.
  • It is not found freely in nature.
  • It reacts strongly in water and bursts into flames when exposed to air.
  • It is silvery white in color.
Common Uses
  • There are few uses for rubidium.
  • Some medical and electronic applications use it.
  • Some research and development teams are testing it in very thin batteries.
  • Some compounds are used in fireworks for a purple color.


Photo Courtesy of
Cary Academy
Chemical Elements
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