86
222.00
Rn
Radon
Identification
CAS Number: 10043-92-2
Discovery Year: 1898
Discoverer: Fredrich Ernst Dorn
Discovery Location: Germany
Properties
Atomic Dimensions
Atomic Radius (Rahm): 243.00000000000003 pm
Covalent Radius: 150 pm →Van der Waals Radius: 220.00000000000003 pm
Thermodynamics
Electronic Structure
Abundance & Geochemistry
Crust Abundance: 4e-13 mg/kg
Sea Abundance: 6e-16 mg/L
Geochemical Class: U/Th decay series
Goldschmidt Class: synthetic
About
Colorless radioactive gaseous element, belongs to the noble gases. Of the twenty known isotopes, the most stable is Rn-222 with a half-life of 3.8 days. Formed by the radioactive decay of Radium-226. Radon itself decays into Polonium. Used in radiotherapy. As a noble gas, it is effectively inert, though radon fluoride has been synthesized. First isolated in 1908 by Ramsey and Gray.
Isotopes
Rn-210 210 ☢ 2.40 h
Rn-211 211 ☢ 14.6 h
Rn-222 222 ☢ 3.82 d
