Name Radon
Symbol Rn
Atomic Number 86
Atomic Mass 222.0 atomic mass units
Number of Protons 87
Number of Neutrons 136
Number of Electrons 87
Melting Point -71.0 C
Boiling Point -61.8 C
Density 9.73 grams per cubic centimeter
Normal Phase Gas
Family Noble Gases
Period 6
Cost $4 per m



Origin of Name From the Latin word nitens, meaning shining
Date and Place of Discovery In 1900 in Halle, Germany
Discovered by Friedrich Ernst Dorn
Common Compounds
Interesting facts
  • It is one of the heaviest gases.
  • It is considered a health hazard.
  • It exists in the decay of radium.
  • Mineral springs in Misasa, Japan, and Bad Kreuznach, Germany are rich in radium and emit radon.
  • The second most frequent cause of lung cancer behind cigarettes.
Common Uses
  • Radon therapy has been used in some spa resorts around the world, but there has never been any proof that there are beneficial effects from radon therapy.
  • Indicator of ground water
  • Earthquake predictor
  • Geothermal prospecting


Photo Courtesy of ChemSoc
Chemical Elements
Robert Wood Johnson Hospital
The Periodic Table
Web Elements

Radon Atomic Structure Elements by Name Elements by Number Home