Radon was discovered by Friedrich Ernst Dorn at 1900 in Germany. William Ramsay and Robert Whytlaw-Gray isolated it and gave it the name 'Niton' in 1908. It has been called radon since 1923.
Atomic number: 86
Atomic weight: 222.02
Group, period, block: 18, 6, p
Color: colorless gas
Classification: noble gases
Electron configuration: 4f14 5d10 6s2 6p6
Density: 9.73 g/L
Melting point: 202.0 K, -71.15 °C, -96.07 °F
Boiling point: 211.3 K, -61.85 °C, -79.1 °F
Oxidation states: 2, 0
Electronegativity: 2.2 (Pauling scale)
Ionization energies: 1st: 1037 kJ·mol-1
Covalent radius: 150 pm
Van der Waals radius: 220 pm
There are three naturally occurring isotopes of radon exist, 219Rn, 220Rn, and 222Rn.