What Does Radon Look Like?

Radon is an invisible radioactive gas. It is a product of the decay of radioactive ores, primarily radium, found in water, soil and rocks throughout the world.

History

Radon was discovered in 1900 by the German physicist Friedrich Ernst Dorn.

Identification

Radon is a radioactive noble gas, designated with the symbol Rn and the atomic number 86 on the periodic table of the elements.

Features

Radon is colorless and odorless at room temperature. When cooled to a solid state, it glows yellow and then orange-red as the temperature falls.

Function

Radon is sometimes used to treat cancer patients. Radon gas also is a byproduct of the radium salt used for the glowing numbers on vintage clocks and watches.

Significance

Indoor exposure to radon is the second-leading cause of lung cancer in the U.S., after smoking. The gas seeps into buildings from surrounding radium, uranium or thorium rock.

Resources

• Radon guide
• The element radium