7th Group Elements in Periodic Table

7th Group Elements does not have a trivial name. The 7th group elements in periodic table include manganese, technetium, rhenium and bohrium. They are explained below.

Manganese – What is It?


Symbol – Mn

Electron Configuration – [Ar] 3d54s2

Atomic Number – 25

Atomic Weight – 54.938


Manganese is a chemical element with the symbol Mn. The origin of name of Manganese is from the Latin word 'magnes', which means magnet and is also said to be derived from the name of black magnesium oxide called magnesia nigra. It is a brittle, silver-grey metal. Manganese has atomic weight of 54.938 and its atomic number is 25. Manganese is a plentiful element that is found throughout much of the earth's crust. However, the metal occurs only in combination with other chemical elements. Minerals that contain large amounts of manganese include braunite, hausmannite, manganite, psilomelane and pyrolusite. Manganese was first isolated as a pure metal in 1774 by Johan Gottlieb Gahn, a Swedish chemist. It has many industrial uses and is especially important in the production of steel. The addition of manganese in the manufacture of steel increases the strength and also improves the workability and resistance to wear. Steels having 13% manganese is called Manganese steel. Manganese steel is used for making the prison bars, rifle barrels, railway tracks and so on.

 

Technetium – What is It?


Symbol – Tc

Electron Configuration – [Kr] 4d55s2

Atomic Number – 43

Atomic Weight – 98.906


Technetium is a chemical element with symbol Tc. It is a radioactive, silvery metal that doesn’t exists in nature. The origin of name is from the Greek word, tekhnetos means artificial. It was the first artificially created element. Its atomic number is 43. The most stable available isotope has an atomic mass number of 98.906. In 1937, Carlo Perrier and Emilio Segre isolated technetium in Italy. They produced it from a sample of molybdenum that had been bombarded with deuterons in the cyclotron of E.O. Lawrence in California, U.S.A. Perrier and Segre proved that the bombardment left one proton in the molybdenum and formed technetium. Scientists first called the element masurium and thought that it occurred in nature. However, only small quantities are produced naturally, so the name was changed to technetium, which means artificial. Technetium is now obtained in large quantities as a by-product from atomic fission. The gamma-ray emitting technetium-99m is extensively used in the application of medical diagnostic researches and in radiology. Some chemical forms are used to figure out some parts of the body. Due to its toxicity, it is not used biologically. It is a extraordinary corrosion inhibitor for steel as a little amount of it can give first rate protection.             

 

Rhenium – What is It?


Symbol – Re

Electron Configuration – [Xe] 4f145d56s2

Atomic Number – 75

Atomic Weight – 186.207


Rhenium is a chemical element with the symbol Re. The origin of name is from the Latin word, Rhenus which means Rhine. It is a rare, costly, silvery-white metal. It is found in small amounts in such minerals as gadolinite and molybdenite. Rhenium has one of the highest melting points of the chemical elements after Tungsten. Because it withstands high temperatures, rhenium is a valuable ingredient in certain alloys. It is sometimes mixed with tungsten or platinum to make heat-resistant electrical equipment. It is also used in making filaments for instruments called mass spectrometers, which are used to measure the mass of charged atoms and molecules. Rhenium was discovered by Ida Tacke, Walter Noddack and Otto Berg in the year 1925. The isolation of rhenium was made by concentrating it from the ore gadolinite which is an impurity. It has an atomic number of 75 and atomic weight is 186.207. Rhenium is used as an additive for the manufacture of alloys of metals, tungsten and molybdenum in order to give additional properties. These alloys are today used in the manufacture of x-ray machines, oven filaments and so on. It can be used as an electrical contact material since it endure the wear and resist arc corrosion.

 

Bohrium (Element 107) – What is It?


Symbol – Bh

Electron Configuration – [Rn] 5f146d57s2

Atomic Number – 107

Atomic Weight – 264


Bohrium is an artificially produced radio active element. It is a highly radio active metal. Two groups of scientists, one from the Soviet Union and one from West Germany, claimed to have created it. Neither claim has been officially accepted. It has an atomic number of 107 and atomic weight is 264. In 1976, Soviet nuclear scientists led by Georgia N. Flerov and Yuri T. Oganessian reported that they had produced an isotope of element 107. They made it by bombarding bismuth 209 with a beam of chromium 54. But officially the element was discovered by Peter Armbruster, Gottfried Munzenberg and their colleagues in 1981. It is named after Danish physicist, Niels Bohr. Bohrium does not occur naturally and it is made only by the cold fusion method. Currently the element is used only for research purposes.