Technetium is totally out of place. It sits smack in the middle of the most solid group of elements around, the transition metals. Virtually all the transition metals are nice stable metals, solid citizens of the periodic table. And here technetium is radioactive! You've got to go a very long way up the list of atomic numbers before you run into another radioactive one (all elements above 83 are radioactive, but below that only 61 promethium and 43 technetium have no stable isotopes). Why technetium is radioactive has to do with the way that protons and neutrons fit together in the nucleus. It's reasonably well understood why technetium can't find a stable configuration, and I think it's fair to say that it boils down to rotten luck. Here's an article about it. Technetium is used for medical imaging, though this application is less popular now than it used to be. It can also be used to inhibit corrosion in steel, though of course it makes the steel radioactive. Detailed Technical Data Compare at other websites: www.webelements.com Los Alamos National Labs Royal Society of Chemistry Toxicology Isotope information Minerals Translations and Etymology Science Fiction (Main Site) Comics Poetry (Main Site) Haiku (Main Site) Collections: Elements I Need Samples Of Atlas of technetium bone scans. This may be as close as I ever come to a technetium sample, given that it's highly radioactive and highly regulated. I do hope to have a real sample some day, but in the mean time, this is a nice book written by a couple of people who seem to have plenty. It's from1978, and from the sound it technetium bone scans were pretty new at the time. Source: eBay seller mycomicsrock Contributor: Theodore Gray Acquired: 5 September, 2002 Price: $1.25 Size: 12" Purity: 0% Sample from the Red Green and Blue Company Element 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. For most sample from this set I have my own picture on the left and the one from the company here, but I haven't taken a picture of this sample yet so there's only one picture. Source: Max Whitby of The Red Green & Blue Company Contributor: Max Whitby of The Red Green & Blue Company Acquired: 25 January, 2003 Price: Donated Size: 0.2" Purity: 0% Sample from the Everest Element 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 (excepted gasses) weight 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. 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 Price: Donated Size: 0.2" Purity: 0%