Category Chemistry

Hafnium is a silvery grey shiny metal. The element is named after Hafnia, the Latin name for Copenhagen, the capital city of Denmark. It is there that the element was discovered.

               Hafnium nuclei has the ability to absorb multiple neutrons; and therefore, it is used in nuclear reactors, especially nuclear powered submarines.

               Dmitri Mendeleev had predicted the possible existence of hafnium. He predicted an element with similar features in his report in 1869. However, it had not been discovered until 1923 by Dirk Coster, a Dutch physicist, and Georg von Hevesy, a Hungarian radio-chemist.

               Hafnium has many interesting features. It reacts with air and forms a film to protect itself. Due to this tendency of the metal, hafnium is very resistant to corrosion. A single fine particle of hafnium can spontaneously combust when it comes in contact with air.

               Hafnium does not exist in nature on its own. It is usually found combined with zirconium to form minerals. Hafnium is used in the manufacture of alloys with several metals, including iron, niobium, titanium, and tantalum.

               Hafnium has the atomic number 72, and it is represented as Hf.

               There is an interesting story behind the naming of the element now known as lutetium. Lutetium was discovered in 1907 independently by three scientists. They were Charles James, an American scientist, Georges Urbain, a French chemist, and Carl Auer von Welsbach, an Austrian mineralogist. When it came to naming the element, there was a dispute among them. Urbain, French by birth, proposed two names, one of which was ‘lutecium’, conceived from Lutetia, the Roman name for Paris. Welsbach had some other ideas. Both of them accused each other of using each other’s research details as well. Anyhow, Urbain’s name was accepted, and it gained popularity with a small change in spelling —from lutecium to lutetium.

               The element has not been isolated until recent years, and it is one of the most difficult ones to prepare. There are very few commercial uses for lutetium because it is too expensive, and too difficult to extract.

               The atomic number of lutetium is 71, and its symbol is Lu.

               Ytterbium is a bright metal with silvery white colour. It is a soft metal, and is both ductile and malleable. The metal tarnishes quickly in air, and reacts slowly with water. Ytterbium is considered to be moderately toxic. Closeness to the  compounds  of ytterbium can cause irritation to skin and eyes.

               Jean Charles Galissard de Marignac, a Swiss chemist, is reputed to have discovered ytterbium in 1878. However, ytterbium as a pure metal was produced only in 1953, at the Ames Laboratory, Iowa, by A. Daane, David Dennison and Frank Spedding. The element is named after Ytterby, a village in Sweden.

               Very rarely is ytterbium found free in nature. However, the element is abundantly available in a number of minerals such as monazite, gadolinite euxenite and xenotime.

               There are many isotopes of ytterbium. Isotope 160Yb is radioactive, and is used in portable x-ray machines that need no electricity. It is used in stress gauges to monitor ground deformations caused by earthquakes or underground explosions. Atomic clocks also use ytterbium for accuracy of time.

               The atomic number of ytterbium is 70, and its atomic symbol is Yb.

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               Yes, thulium is used in Euro banknotes to prevent counterfeiting. The element  in the note displays blue fluorescence under ultraviolet light thus aiding in distinguishing between the real and the fake currency note.

               Thulium gets its name from the name of an ancient place called Thule which is associated with Scandinavia. Per Teodor Cleve, the Swedish chemist discovered two new materials, one green and one brown, while working with erbia (erbium oxide) in 1879, in Uppsala, Sweden. These turned out to be oxides of two new elements: thulium and holmium. The green substance he named thulia, which he later found to be thulium oxide, and the brown substance he named holmia, which he later found to be holmium oxide. Charles James in New Hampshire prepared the first pure thulium in 1911.

               This element does not have many uses as it is rare, and therefore, costly. There are many cheaper elements that can substitute thulium. It is used in laser equipment and X-ray devices. The atomic number of thulium is 69, and its atomic symbol is Tm.

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               As we have already seen, many elements were discovered in the Swedish village Ytterby. The element erbium was one among them, and was discovered in 1843. It was the Swedish chemist Carl Gustaf Mosander who discovered the element. Mosander was working with a sample of what was thought to be the single metal oxide yttria, derived from the mineral gadolinite. He extracted three segments from it and called them yttria, erbia and terbia. As might be expected considering the similarities between their names and properties, scientists soon confused erbia and terbia. Mosander’s terbia became known as erbia after 1860, and the earlier known erbia was renamed terbia after 1877!

               It is difficult to find natural erbium independently on earth as it is always found in chemical compounds. Erbium has a special ability to absorb harmful infra-red rays. Therefore, the element is used in the glass of safety goggles for welders.

               Erbium occurs in a variety of minerals, including gadolinite, euxenite, xenotime, fergusonite, polycrase and blomstrandine.

               The atomic number of erbium is 68, and its symbol is Er.

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               Stockholm is the capital city of Sweden. Holmium is named after this city which is known as   Holmia in Latin.

               The element was discovered spectroscopically by Marc Delafontaine and Jacques-Louis Soret in 1878. Per Teodor Cleve, a Swedish chemist, discovered the element independently in 1879, and he named it after his hometown, Stockholm. The pure metal was isolated in 1911, by Otto Holmberg.

               Holmium is a bright, soft, silvery white element. The element has some special magnetic properties and they enable holmium to be used in alloys for the production of magnets. Holmium magnets can, in fact, create the strongest magnetic fields. Holmium is also used in nuclear reactors.

               Holmium is not generally seen as a free element in nature but is found in compounds in a number of minerals such as gadolinite and monazite.

               It is commercially extracted from monazite and occurs in that mineral at a rate of about 0.05 per cent.

               Holmium is mainly used in laser surgery. There are not many commercial uses for the element.

               The atomic number of holmium is 67, and it is represented as Ho.

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