History: Yttrium was discovered by Johan Gadolin, a Finnish chemist, in 1794 while analyzing the composition of the mineral gadolinite ((Ce, La, Nd, Y)2FeBe2Si2O10) in 1789. Yttrium is named after Ytterby, Sweden. Yttrium is a highly crystalline iron-gray, rare-earth metal.
| Johan Gadolin |
Uses:
1. The largest use of yttrium is in the form of yttrium(Ill) oxide, which is used to produce phosphors which give the red colour in colour television tubes.
2. It is also used in the making of microwave filters.
3. Yttrium is often used as an additive in alloys, and increases the strength of aluminium and magnesium alloy.
4. It is also used as a detoxifier for non-ferrous metals. It has been used as a catalyst in ethylene polymerisation.
5. Yttrium-90, a radioactive isotope, has a medical use in needles which have replaced the surgeon’s knife in killing pain-transmitting nerves in the spinal cord.
| phosphors give the red colour in colour television tubes |
Process: Today, yttrium is primarily obtained through an ion exchange process from monazite sand ((Ce, La, Th, Nd, Y)PO4), a material rich in rare earth elements and bastnaesite by reduction with calcium metal.
Physical Properties: In 1843, Carl Mosander investigated yttrium oxide more thoroughly and found that it consisted of three oxides: yttrium oxide, which was white; terbium oxide, which was yellow; and erbium oxide, which was rose-coloured. It is a silvery metal, which is stable in air because of an oxide film that forms on its surface.
39
Atomic mass
88.9059 g.mol -1
Electronegativity according to Pauling
1.2
Density
4.47 g.cm-3 at 20°C
Melting point
1500 °C
Boiling point
3336 °C
Chemical Properties: Yttrium reacts with cold water slowly and with hot water very rapidly. It dissolves in both acids and alkalis. Solid yttrium metal does not react with oxygen in the air. However, it reacts very rapidly when in its powdered form. Yttrium powder may react explosively with oxygen at high temperatures.
Neodymium
Atomic Number: 60
Atomic Weight: 144.242
Melting Point: 1294 K (1021 C)
Boiling Point: 3347 K (3074 C)
Density: 7.01
Room Temperature State: Solid
Discovery
Neodymium was discovered in 1885 by a researcher named Carl F. Auer. He obtained the rare earth metal through an ion exchange with a common chemical in some rare earth metals, monazite sand.
Physical Properties:
-Bright, silvery look to it
-Very reactive
-Oxidizes in air
Chemical Properties:
-Tarnishes slowly in air
-Very easy to burn
-Reacts slowly in cold water
-Very reactive with all the halogens
Uses:
Neodymium is used as fertilizer in China. Many compounds of rare earth metals are used in China for fertilization because they promote plant growth, similar to Ca2+. It is also used in samarium-neodymium dating, which is a very exact and useful process for determining the age of rocks and meteors. Another use for the element is in determining the size and strength of a volcanic eruption. By scanning the neodymium isotopes in the volcano, scientists can warn the residents living near the volcano of the intensity of the upcoming eruption.
One of the most common uses for neodymium is in magnets. Neodymium magnets are the strongest permanent magnets known to man, and can lift a thousand times its own weight. They are very cheap to make and fairly light as well, making them better and more useful than the samarium-cobalt magnets. The magnets are used in a multitude of products:
-microphones
-speakers
-in-ear headphones and normal headphones
-guitar and bass guitar pick-ups
-hard disks
Neodymium magnet motors were created in 2010, and are now replacing many motors. They are electric, and can be found in hybrid cars and wind turbines.
We know neodymium for its use in iPhone screen color. Neodymium, being highly reactive, reacts with of elements to create the thousands of different colors we see on our iPhone screens.
Occurrence:
Neodymium is not in the least bit rare. The main countries that mine neodymium is China, Australia, Brazil, and the United States. It is estimated that the reserves of neodymium that are still not mined are 8 million tonnes. In the Earths crust, neodymium's abundance is about 10% - 18%. It is the most common rare earth metal, besides cerium present in the earth's crust.
Uranium
Uranium Production:
World-wide uranium productions amounted to 50,572 tonnes. Kazakhstan, Canada, and Australia are the top three producers and together account for 63% of world uranium production. Other major Uranium Producing Countries are Namibia, Russia, Niger, Uzbekistan, and the United States producing about 1000 tonnes per year are
Uranium Uses
The most common use of Uranium is to power nuclear plants. As of 2008, known uranium ore resources that can be mined at about current costs are estimated to be sufficient to produce fuel for about a century, based on current consumption rates.
Uranium History
The use of uranium in its natural oxide form dates back to at least the year 79 CE, when it was used to add a yellow color to ceramic glazes. Yellow glass with 1% uranium oxide was found in a Roman villa on Cape Posillipo in the Bay of Naples, Italy by R. T. Gunther of the University of Oxford in 1912. Starting in the late middle Ages, pitchblende was extracted from the Habsburg silver mines in Joachimsthal, Bohemia (now Jáchymov in the Czech Republic) and was used as a coloring agent in the local glassmaking industry. In the early 19th century, the world's only known sources of uranium ore were these mines.
Physical/Chemical Properties
Uranium is a hard, dense, malleable, ductile, silver-white, radioactive metal. Uranium metal has very high density. When finely divided, it can react with cold water. In air it is coated by uranium oxide, tarnishing rapidly. It is attacked by steam and acids. Uranium can form solids solutions and intermetallic compounds with many of the metals.
Abundance:
Uranium is very abundant. In fact, the world’s largest known resources increased by 15% in the last two years.
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