Radon: Properties, uses, history, and isotopes

Radon, symbol Rn on the periodic table, has the atomic number 86 and belongs to group 18 of the noble gases. It is a radioactive, colourless, odourless, inert, and tasteless gas produced by the natural radioactive decay of uranium present in most soils and rocks.

It has no direct commercial uses, except as a radiation standard for calibrating radon monitoring equipment and for research as a tracer gas (used in environmental studies to track the movement of air and water), earthquake prediction, atmospheric studies, and oil and uranium exploration.

Source: Knowledge Archive

Radon isotopes

There are three common ‘varieties’ or isotopes of radon in nature, two of which pose a health risk, radon-220 and radon-222, and a third, radon-219, which is not considered dangerous.

The most dangerous is radon-222 (a product of the decay of uranium-238 or radium-226). Given that it has a relatively long half-life, this variety can accumulate indoors. It is quite common due to the high concentrations of uranium-238 in the soil in some parts of the world and the different concentrations of radium in some building materials. Sometimes, radon-222, together with radon-220 (a product of the decay of thorium-232), is the main source of public exposure to radiation. However, these two types of radon require the same protective measures.