Technetium

Technetium below Uranium in the periodic element is actually the only element which does not naturally occur, this means that it cannot be found normally existing on earth. The element therefore has to be created through a process of nuclear reaction rather than being found on the earth. Technetium was discovered after there had been years of an empty space in the periodic table with nobody being able to fill up the gap. In 1925 the element was finally discovered and only ten years later was it actually produced for the first time. Isotopes as you must know are different forms of the same element. These isotopes are quite similar to each other but also have properties that are absolutely the opposite, in either case every isotope is differentiated from the other through its difference in mass number.

As you will read on you will find among the most important properties being talked about the isotopes of the element is its life; and in most of such radioactive isotopes the life span of the isotope is described in terms of its “half life”. So half life actually means the length of time that half of the element would exist or the amount of time half of the element would take to decay or breakdown. So supposing you have the isotope – technetium 97 of ten grams then after a million years only 5 grams will remain. This means that the half life of this particular isotope is a million years. However the process of decay after that is also very simple. That after a million years only 2.5grams of the 5grams of technetium will remain, similarly after a million years half of the 2.5grams will remain. So the process of decay of these isotopes is in this fashion.

Technetium is the lightest radioactive element in the Periodic table and thus as you can deduce has no stable isotopes. Most of the isotopes of the Technetium element hardly have a life span of less than an hour, excepting around three isotopes most of them have such a life span; the other three as well which includes Tc 99 have half lives that last for more than a few hours and some a few days but none of the isotopes are stable enough to last longer. The most stable isotope among all of those of the Technetium element is Tc 98 while the most commonly used isotope for commercial purposes and also the isotope that is most readily available is Tc 99. This is because the short life of this isotope is perfect for its use in nuclear medicine and for detection and imaging. This isotope has actually been produced in great bulks over the years as it can be created very easily through fission of the uranium element in a nuclear reactor. It decays by emitting gamma rays which is great for the work that they use the isotope for. Also the extremely long half life of the isotope, which is some million years makes it safe for usage for medical purposes as the chances of radioactive hazards is thus limited. There is also actually another radionuclide which is known as technetium 99m which has an extremely short span of half life, of only six hours. This one is produced out of the decay of another radionuclide Molybdenum 99. This one produces technetium 99m when it starts to decay, having a half life itself of sixty six hours.

As per reports there are about twenty two isotopes of the element that have been found ranging in mass from 90 to 111. As expected all these isotopes are actually radioactive; while most as mentioned are short lived being unstable only three have a long life; these are isotopes:97,98,99.  However the most importance and most studies are based directly on technetium 99 because of its widespread use. Technetium 98 also like 99 also actually decays in similar way, that is by emitting beta particles but the other stable isotope 97 decays by electron capturing.

Besides these, most of the other technetium isotopes such as 84, 89, 93, 97 all have their modes of decay as electron capture; there are a few towards the end of the list of technetium isotopes, those such as 100, 102, 108 etc are the isotopes that have Beta Minus Decay as their method of decomposition and decay, these are for those isotopes that are heavier than the others. There are also a few on the list that disintegrate through some Isomeric transitions; these will include 86m, 93 m2, 102 m and a few others.

All isotopes of technetium thus should be handled with a certain amount of care as they are all radioactive. Tc 99 especially is one of those isotopes of the element that could easily cause contamination hazards and so must be handled with special care with the usage of glove boxes and fume masks etc. Most of these isotopes, as is the case of the element itself has no reason to be used normally in daily life as such and thus should be used only for laboratory and research work and for these cases they should be handled with care. The gamma rays that are emitted are not as such very harmful as they are weak and do not carry too far; also usually in laboratories there is the glassware of the walls of the lab that would stop all kinds of dust of the element along with fumes to be blocked, but it is safest to stay at least some distance away from the walls from the outside of the laboratory as well, just for safe keeping. As in the case of most of the isotopes especially the more stable ones, proper care and precautions need to be maintained while they are being handled. However, all the other isotopes as well have no biological role; so would not be used for any daily purposes except for research requirements.