The 99 refers to the 43 protons plus 56 neutrons in its nucleus. And the m refers to a specific configuration of those particles. The result is an atom that decays within a few hours, generating gamma rays - radiation that can be used to produce medical images.
At UCL Hospital in London, Sarah is about to undergo just such a scan to look at her spine, ahead of an operation to fuse two of her vertebrae. First, she has to be injected with the technetium. Her doctor assays the dose - the technetium is continually decaying, so it is important to check that it is still sufficiently radioactive to produce an image, but not enough to be harmful. The injection does not just contain technetium. Each radioactive atom is attached to a "ligand" - a chemical that ensures the technetium reaches the right part of Sarah's body.
In this case, the ligand is a phosphonate - a type of salt that is absorbed from the blood by bones. And this is the magic of the technetium scan. It generates a telling pattern of hot spots - hives of activity where the bone may be repairing itself and has therefore absorbed more phosphonate from the blood - and cold spots where the bone may be dead.
Before she can be scanned, Sarah has to wait four hours for the technetium to find its way to her spine, during which time she is advised to avoid close contact with small children as she is mildly radioactive. After the four hours, there is a short window of time during which the scan can be done.
Wait too long, and the technetium will decay away altogether - it has a half-life of six hours - or be flushed out of Sarah's body.
Upon her return, she is slowly put through a full-body scanner that detects the gamma-ray emissions, and uses that data to create a three-dimensional image of what is happening in her spine. Bone is just one material that technetium can be used to peer at.
By attaching it to other chemical ligands, this radioactive marker can be towed through the body's metabolic pathways to other organs - the spleen, lungs, liver, lymph glands, heart. Moreover, it's not just the ligand that can be switched. The technetiumm itself is merely the most versatile and commonly used of an entire suite of radioactive isotopes, each of which has a different half-life, and different radioactive and chemical properties, attuned to detecting particular diseases in the body.
Iodine - diagnosis, particularly of the thyroid, and of neurological disease such as Alzheimer's and Parkinson's.
Iodine - treating thyroid disease, including cancer. Fluorine - imaging malignant tumours. Thallium - monitoring the heart during exercise. Gallium - imaging tumours and locating inflammatory lesions.
Indium - locating blood clots, inflammation and rare cancers. Xenon - inhaled for studying lung ventilation. To obtain the best experience, we recommend you use a more up to date browser or turn off compatibility mode in Internet Explorer.
In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript. The story of the last element to be discovered out of the first 92 catalogued in the periodic table is told by Eric Scerri , who reminds us that technetium can be found a little closer to home than many of us might think.
Group 7 of the periodic table is something of an oddity. When the first periodic table was formulated by Mendeleev, it was the only group that contained just a single known element — manganese.
In the early twentieth century, several claims were made for the discovery of the element immediately below manganese. But this alleged element, given various names such as davyum, illenium, lucium and nipponium, turned out to be spurious. Then, in , Otto Berg, Walter Noddack and Ida Tacke later Ida Noddack , claimed to have discovered not just one but two new members of Group 7, which they named masurium and rhenium.
Although their discovery of rhenium was soon accepted, their claim for the element directly below manganese has been bitterly disputed 1 , 2 , 3 , 4 , 5 ever since. As recently as the turn of the millennium, Belgian physicist Pieter van Assche collaborated with several US spectroscopists to re-analyse the original X-ray images. They then argued that the Noddacks had in fact isolated another element in addition to rhenium. But this claim has also been disputed by a number of other researchers.
Technetium, as they called it, was the last of elements to be tracked down, and in fact it had to be synthesized rather than isolated from naturally occurring sources. It is also the only element to ever be 'discovered' in Italy — in Palermo, Sicily, to be more precise. Various chemical analyses by the Italian team revealed a new element, which could be extracted by boiling with sodium hydroxide that also contained a small amount of hydrogen peroxide. Over the next couple of years we refined our reconstruction of their analytical methods and performed more sophisticated simulations.
The agreement between simulated and reported spectra improved further. Our calculation of the amount of element 43 required to produce their spectrum is very similar to the direct measurements of natural technetium abundance in uranium ore published in by Dave Curtis et al.
We can find no other plausible explanation for their data, than that they did indeed detect fission masurium. The Noddacks were clearly among the fi. Pub Type.
Armstrong, J. Created August 26, , Updated February 17, Technetium is the lightest radioactive element on the periodic table and its isotopes decay into a variety of other elements including stable ruthenium.
So while it's highly unlikely we'll ever find a mother lode of technetium on Earth, it has been detected in the spectra of some stars, confirming the theory that elements are produced by nuclear reactions within stars. Technetium isotopes are also found occasionally in naturally-occurring 'reactors', says Weiner.
These reactors are uranium deposits which naturally underwent sustained nuclear reactions in Gabon, western Africa about 1. Technetium isotopes like the excited isotope technetiumm are produced today because of their importance in nuclear medicine. The big advantage of technetiumm half-life six hours is that it is produced by decay from the much longer lived isotope molybdenum half-life 67 hours.
This means molybdenum can be stored in the hospital and the technetiumm isolated for patient use when necessary. ANSTO's OPAL reactor produces molybdenum using uranium, and ANSTO is hoping to increase its production of this isotope with the world facing a potential shortfall in supplies as older reactors are temporarily closed for maintenance.
Technetiumm is a good isotope to use as a radioactive tracer because it doesn't harm the body too much, and the single gamma ray it emits enables doctors to get a very good picture of where the isotope is in the body, Weiner says.
However the downside of the procedure is it produces waste in the form of technetium the ground or unexcited state of technetiumm which has to be immobilised to prevent harm to the environment.
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