Atomic Number:	88
Atomic Symbol:	Ra
Atomic Weight:	226.0254
Electron Configuration:	[Rn]7s2

At ordinary temperatures radon is a colourless gas. When cooled below the freezing point, radon
exhibits a brilliant phosphorescence which becomes yellow as the temperature is lowered and
orange-red at the temperature of liquid air. The main hazard is from inhalation of the element and its
decay products which are collected on dust in the air. Recently, radon buildup in homes from the
surrounding soil and rocks has become a safety issue and some areas around the world test homes for radon gas. It is the heaviest known gas and is present in some spring waters.