Unstable elements undergo radioactive decay into stable elements. 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.
Tags: nuclear-issues , medical-procedures , chemistry. Email ABC Science. If technetium does exist organically, it must be in minute concentrations. Technetium has been found in the spectrum of S-, M-, and N-type stars. Its presence is leading to new theories of the production of heavy elements in the stars. As was found in , one of its isotopes, 99 Tc, is produced as a product from the fission of uranium in nuclear reactors. Because of this, large quantities have been produced over the years.
There are kilogram-sized quantities of technetium currently in existence. Technetium is a remarkable corrosion inhibitor for steel. Mild carbon steels may be protected by as little as 55 ppm of KTcO 4 in aerated distilled water at temperatures up to C F. In fact, it was not until more than ten years later that the element was finally produced. Then, it was created in a particle accelerator and not found on Earth.
Today, technetium has very few—but very important—uses. It is used in finding out more about diseases and health problems. It is also used to make steel stronger. In the s, a team of researchers were looking for elements with atomic numbers 43 and In , the team announced that they had found both elements.
They named element 43 masurium, after the region called Masurenland in eastern Germany, and element 75 rhenium, after the Rhineland, in western Germany. Although they were correct about rhenium, they were wrong about masurium.
No other chemist was able to reproduce masurium. So, chemists kept looking for element It was finally discovered in the products of a particle accelerator experiment at the University of California at Berkeley.
A particle accelerator is sometimes called an atom smasher. It accelerates small particles, such as protons, to very high speeds. The particles then collide with elements such as gold, copper, or tin. When struck by the particles, the targets often form new elements. These researchers collected one ten-billionth of a gram of the element and studied some of its properties. They eventually gave the name technetium to the element, from the Greek word technetos, meaning "artificial.
It can now be made in much larger quantities, of at least a kilogram two pounds at a time. Technetium is placed between manganese and rhenium on the periodic table.
That would lead chemists to believe that its properties are like those of the other two elements. Experiments have shown this to be true. It reacts with some acids, but not others. It also reacts with fluorine gas and with sulfur at high temperatures. Some scientists believe that technetium will be found in very small amounts in the Earth's crust along with other radioactive materials, such as uranium and radium. However, it has never been found on Earth.
It has, however, been found in certain types of stars. Its presence can be detected by analyzing the light produced by these stars. All isotopes of technetium are radioactive. The most stable of these isotopes technetium, technetium, and technetium, have half lives of more than a million years. Isotopes are two or more forms of an element. Isotopes differ from each other according to their mass number. The number written to the right of the element's name is the mass number.
The mass number represents the number of protons plus neutrons in the nucleus of an atom of the element. The number of protons determines the element, but the number of neutrons in the atom of any one element can vary. Each variation is an isotope. The half Life of a radioactive element is the time it takes for half of a sample of the element to break down.
0コメント