HHomeBackground Color:He
LiBeRadon Pictures PageBlack White GrayBCNOFNe
NaMgRadon Technical DataAlSiPSClAr
KCaRadon Isotope DataScTiVCrMnFeCoNiCuZnGaGeAsSeBrKr


Atomic Weight 222[note]
Density 9.73 g/l[note]
Melting Point -71 °C
Boiling Point -61.7 °C
Full technical data

Radon is an invisible, radioactive gas, thus hard to photograph. This granite ball reminds us that the source of most radon in people's basements is the decay of traces of uranium and thorium in granite bedrock.

Scroll down to see examples of Radon.
The Elements book Mad Science book Periodic Table Poster  Click here to buy a book, photographic periodic table poster, card deck, or 3D print based on the images you see here!
Radon Electronic radon gas detector

Electronic radon gas detector.
Continuous electronic radon gas monitor that reads out in Pico-curies per liter. You can choose between averaging over a few days, or over the whole time the monitor has been installed.
Source: Catalog
Contributor: Theodore Gray
Acquired: 29 April, 2009
Text Updated: 28 June, 2009
Price: $120
Size: 5"
Purity: 0%
Radon Single-use radon gas detector

Single-use radon gas detector.
Small vial you put in your basement for a couple of days, then mail in to a lab for testing, to see how much radon you've got.
Source: Hardware Store
Contributor: Theodore Gray
Acquired: 29 April, 2009
Text Updated: 30 April, 2009
Price: $10
Size: 2"
Purity: 0%
Radon Radium bath house postcard

Radium bath house postcard.
Postcard about a radium bath house, listed here because most of the radioactivity in the water was probably from radon, not radium.
Source: eBay seller beckyj29
Contributor: Theodore Gray
Acquired: 25 April, 2009
Text Updated: 25 April, 2009
Price: $1.25
Size: 6"
Purity: 0%
Radon Granite sphere

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Granite sphere.
Radon is a hard element to pin down: You can't see it because it's a clear gas, and you can't even have a vial of it because it's extremely radioactive and has a half life of only 3.2 days. One place it can be found, if only in microscopic and invisible quantities, is in granite rocks. Granite contains uranium and thorium impurities, which constantly give off small amounts of radon gas. This is why areas of the country with certain kinds of bedrock also have problems with radon collecting in basements. And it's why large granite buildings are measurably more radioactive than normal.

I chose this sample to represent its element in my Photographic Periodic Table Poster. The sample photograph includes text exactly as it appears in the poster, which you are encouraged to buy a copy of.
Periodic Table Poster

Source: Kinetic Fountains
Contributor: Theodore Gray
Acquired: 10 August, 2005
Text Updated: 4 May, 2007
Price: $120
Size: 10"
Purity: 0.00001%
Radon Sample from the Everest Set

Sample from the Everest Set.
Up until the early 1990's a company in Russia sold a periodic table collection with element samples. At some point their American distributor sold off the remaining stock to a man who is now selling them on eBay. The samples (except gases) weigh about 0.25 grams each, and the whole set comes in a very nice wooden box with a printed periodic table in the lid.

Radioactive elements like this one are represented in this particular set by a non-radioactive dummy powder, which doesn't look anything like the real element. (In this case a sample of the pure element isn't really practical anyway.)

To learn more about the set you can visit my page about element collecting for a general description and information about how to buy one, or you can see photographs of all the samples from the set displayed on my website in a periodic table layout or with bigger pictures in numerical order.

Source: Rob Accurso
Contributor: Rob Accurso
Acquired: 7 February, 2003
Text Updated: 18 January, 2009
Price: Donated
Size: 0.2"
Purity: 0%
Radon Sample from the RGB Set

Sample from the RGB Set.
The Red Green and Blue company in England sells a very nice element collection in several versions. Max Whitby, the director of the company, very kindly donated a complete set to the periodic table table.

To learn more about the set you can visit my page about element collecting for a general description or the company's website which includes many photographs and pricing details. I have two photographs of each sample from the set: One taken by me and one from the company. You can see photographs of all the samples displayed in a periodic table format: my pictures or their pictures. Or you can see both side-by-side with bigger pictures in numerical order.

The picture on the left was taken by me. Here is the company's version (there is some variation between sets, so the pictures sometimes show different variations of the samples):

Source: Max Whitby of RGB
Contributor: Max Whitby of RGB
Acquired: 25 January, 2003
Text Updated: 11 August, 2007
Price: Donated
Size: 0.2"
Purity: <2%
Radon Radon generating thorium oxide

Radon generating thorium oxide.
The longest-lived isotope of radon has a half-life of only 3.8 days, which means you can't really collect and store a sample of radon: It would be completely gone within a few weeks. But you can seal up some thorium oxide in a glass tube and be sure you always have some. Radon is one of the decay products of thorium, and there will always be some radon gas trapped in the tube. The concentration should be fairly constant, because thorium has a very long half-life while radon has a very short one: There should by now exist in this tube an equilibrium concentration of radon, which perhaps some helpful reader will calculate for me (necessary information: ca. 0.5g of thorium oxide in ca. 0.5cc volume tube).

The source of this tube, Gillian Pearce, reports that thorium oxide is a better source of radon than is pure thorium metal (which I have much more of), because the radon can't escape from the metal and remains trapped there as it decays.

Mike Seifert, a graduate student in Physics at the University of Chicago, wrote to me with a calculation of how much radon he thinks is in my tube:
Since you asked on your radon page: by my calculations, you have about 5.2 * 10^-17 grams of radon in your tube of thorium oxide. The source of this number is essentially (after a moderate amount of math):

mass of radon = (Rn half-life)/(Th half-life) * (Rn_220 AW) / (Th O_2 MW) * mass of Th O_2

Since the radon-220 lifetime is about 56 seconds while that of thorium-232 is about 1.4 billion years, there really ain't much radon in there... Another way to think about it is that the partial pressure of the radon in the tube is about 1.2 * 10^-6 Pascals, or about 9 * 10^-9 torr. Still better than outer space by about two or three orders of magnitude, though. Ah well, it's the thought that counts. :-)

Source: eBay seller rubbleshop
Contributor: eBay seller rubbleshop
Acquired: 19 October, 2002
Price: Donated
Size: 1"
Purity: <1%
Radon Photo Card Deck of the Elements

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Photo Card Deck of the Elements.
In late 2006 I published a photo periodic table and it's been selling well enough to encourage me to make new products. This one is a particularly neat one: A complete card deck of the elements with one big five-inch (12.7cm) square card for every element. If you like this site and all the pictures on it, you'll love this card deck. And of course if you're wondering what pays for all the pictures and the internet bandwidth to let you look at them, the answer is people buying my posters and cards decks. Hint hint.
Source: Theodore Gray
Contributor: Theodore Gray
Acquired: 19 November, 2008
Text Updated: 28 October, 2017
Price: $35
Size: 5"
Composition: HHeLiBeBCNOFNeNaMg AlSiPSClArKCaScTiVCrMn FeCoNiCuZnGaGeAsSeBrKr RbSrYZrNbMoTcRuRhPdAg CdInSnSbTeIXeCsBaLaCePr NdPmSmEuGdTbDyHoErTm YbLuHfTaWReOsIrPtAuHgTl PbBiPoAtRnFrRaAcThPaUNp PuAmCmBkCfEsFmMdNoLrRf DbSgBhHsMtDsRgCnNhFlMcLvTsOg
The Elements book Mad Science book Periodic Table Poster  Click here to buy a book, photographic periodic table poster, card deck, or 3D print based on the images you see here!