Name radon
Symbol Rn
Atomic Weight 222.02
Atomic Number 86
CAS ID 10043-92-2
Group Number 18
Group Name Noble Gas
Period Number 6
Origin of Name Named after the element radium.
Year Discovered 1900
Discovery Credits Discovered by F. E. Dorn at Halle, Germany.
Class Non-Metallic
Color Colorless
Standard State Gas at 77 F & 298 K (The heaviest known mononuclear gas)
Description Colorless, odorless gas produced by radioactive decay of radium. Little studied because of hazardous radiation which destroys any compounds that are formed. Chemically should be like xenon. Radon is present in uranium and thorium minerals as a radioactive gas which can enter the atmosphere. 

Back to Elements Table Page