Jonathan Kirk

Period 6

1/22/05

Radon

Atomic number: 86

Atomic symbol: Rn

Atomic weight: 222

Electron configuration:[Xe]6s²4f¹⁴5d¹⁰6p⁶

^{Melting point: -71 ºC}

On the average, one part of radon is present at 1 x 1021 part of air and is a colorless gas at ordinary temperature.. When cooled below freezing point, however, radon exhibits a brilliant phosphorescence which becomes yellow as the temperature is lowered and orange-red at the temperature of liquid air.

Radon is radioactive

Radon is still produced for therapeutic use by a few hospitals by pumping it from a radium source and sealing it in minute tubes, called seeds or needles, for application to patient. This practice has been largely discontinued as hospitals can get the seeds directly from suppliers, who make up the seeds with the desired activity for the day of use.