Periodic table is a chart that displays 118 chemical elements organized into rows or periods based on their atomic structures. Over a long period of time, there was no element at the number 43. Italian physicists namely Carlo Perrier and Emilio Segre found the element 43 and named it Technetium. It was derived from the Greek word "technetos" meaning “artificial”. Technetium is represented by the symbol Tc. Technetium does not exist naturally on earth. It is a man-made element produced by particle acceleration. Few scientists believe that it can be found along with other radioactive elements like uranium and radium. However, they failed to support their statement. Technetium is generally produced in the nuclear reactors when neutrons collide with uranium or plutonium atoms.
There were 5 empty slots in the periodic table that created interest among many scientists. In the 1920’s, a team of German chemists including Walter Noddack, Ida Tacke, and Otto Berg started looking for elements with atomic number 43 and 75. In 1925, they claimed to have found both the elements and named element 43 as masurium (after the region called Masurenland in Germany) and element 75 as rhenium (after Rhineland in Germany). They were right about element 75. Unfortunately, element 43 could not be replicated by any other scientists. Hence the discovery was discarded as an error. In 1936, Italian physicist Emilio Segre and his colleague Carlo Perrier discovered technetium in a particle accelerator experiment conducted at the University of California, Berkeley. A particle accelerator, eject small particles such as protons to a very high speed. These particles collide with elements like gold, copper or tin giving rise to new elements.
Technetium is a silver-grayish radioactive metal that resembles platinum in appearance. It is generally obtained in powdery form.
It has a very high melting point of 2,200°C.
The density of technetium is 11.5 grams per cubic.
The metal form of technetium is slightly paramagnetic in nature. The magnetic dipoles of the metal align with external magnetic poles.
Technetium is placed between rhenium and manganese in the 7th group of the periodic table. It closely resembles rhenium in its chemical properties and has the tendency to form covalent bonds.
Technetium is easily soluble in nitric acid (HNO3), sulfuric acid (H2SO4), and hydrochloric acid (HCL).
Isotopes are where the atoms within an element have the same number of protons but different number of protons which results in them having the same atomic number but different masses. So basically, isotopes vary in their mass numbers such as 12C and 14C. The mass number is the sum of the number of protons and neutrons present in the nucleus of an atom. Technetium is the lowest numbered element in the periodic table. All of its isotopes are radioactive. The most stable technetium isotopes are technetium-97, technetium-98, and technetium-99. All the isotopes have half-lives longer than 80 million years. Technetium-99 is the most abundant and readily available isotope. It is obtained from uranium fission.
Technetium has several applications in the industrial, chemical, and medicincal industry.