CHEMISTRY GLOSSARY

molybdenum    →   molibden

Molybdenum was discovered by Carl William Scheele (Sweden) in 1778. The origin of the name comes from the Greek word molybdos meaning lead. It is silvery white, very hard metal, but is softer and more ductile than tungsten. Molybdenum is found in the minerals molybdenite (MoS₂) and wulfenite (MoO₄Pb). Its alloys are used in aircraft, missiles and protective coatings in boiler plate.

neodymium    →   neodimij

Neodymium was discovered by Carl F. Auer von Welsbach (Austria) in 1885. The origin of the name comes from the Greek words neos didymos meaning new twin. It is silvery-white, rare-earth metal that oxidizes easily in air. Reacts slowly in cold water, more rapidly as heated. Metal ignites and burns readily. Neodymium is made from electrolysis of its halide salts, which are made from monazite sand. Used in making artificial ruby for lasers. Also in ceramics and for a special lens with praseodymium. Also to produce bright purple glass and special glass that filters infrared radiation. Misch metal, used in the manufacture of pyrophoric alloys for cigarette lighters, contains about 18 % neodymium metal. (Typically composition of misch metal are Ce:Nd:Pr:La:Other rare earth=50:18:6:22:4). Neodymium is used to create some of the most powerful permanent magnets on Earth, known as NIB magnets they consist of neodymium, iron, and boron.

nerve poison    →   živčani bojni otrov

Nerve poison (nerve gas, agents) have had an entirely dominant role since the Second World War. Nerve poisons acquired their name because they affect the transmission of nerve impulses in the nervous system. All nerve poisons belong chemically to the group of organo-phosphorus compounds. They are stable and easily dispersed, highly toxic and have rapid effects both when absorbed through the skin and via respiration. Nerve poisons can be manufactured by means of fairly simple chemical techniques. The raw materials are inexpensive and generally readily available.

The most important nerve agents included in modern chemical weapons arsenals are:

Nerve poisons are colorless, odorless, tasteless liquids of low volatility. Antidotes are atropine sulfate and pralidoxime iodide.

nickel    →   nikal

Nickel was discovered by Axel Fredrik Cronstedt (Sweden) in 1751. The origin of the name comes from the German word kupfernickel meaning Devil’s copper or St Nicholas’s (Old Nick’s) copper. It is hard, malleable, silvery-white metal. Soluble in acids, resist alkalis. It can be polished to a lustrous finish. Resists corrosion in air under normal conditions. Nickel is chiefly found in pentlandite [(Ni,Fe)₉S₈] ore. The metal is produced by heating the ore in a blast furnace which replaces the sulfur with oxygen. The oxides are then treated with an acid that reacts with the iron not the nickel. Used in electroplating and metal alloys because of its resistance to corrosion. Also in nickel-cadmium batteries, as a catalyst and for coins.

niobium    →   niobij

Niobium was discovered by Charles Hatchett (England) in 1801. The origin of the name comes from the Greek word Niobe meaning daughter of Tantalus in Greek mythology (tantalum is closely related to niobium in the periodic table). It is shiny white, soft, ductile metal. Exposed surfaces form oxide film. Niobium occurs in a mineral columbite. It is used in stainless steel alloys for nuclear reactors, jets and missiles. Used as an alloy with iron and nickel. It can be used in nuclear reactors and is known to be superconductive when alloyed with tin, aluminium or zirconium.

nobelium    →   nobelij

Nobelium was discovered by Nobel Institute of Physics in Stockholm and later by Albert Ghiorso, Torbjorn Sikkeland, J. R. Walton and Glenn T. Seaborg (USA) in 1958. Named in honour of Alfred Nobel, Swedish chemist who discovered dynamite and founder of the Nobel Prizes. It is synthetic radioactive metal. Nobelium was made by bombarding curium with carbon-13.

nuclear reactor    →   nuklearni reaktor

Nuclear reactor is an assembly of fissionable material (uranium-235 or plutonium-239) designed to produce a sustained and controllable chain reaction for the generation of electric power.

The essential components of a nuclear reactor are:

1. The core, metal rods containing enough fissionable material to maintain a chain reaction at the necessary power level (as much as 50 t of uranium may be required).
2. A source of neutrons to initiate the reaction (such as a mixture of polonium and beryllium)
3. A moderator to reduce the energy of fast neutrons for more efficient fission (material such as graphite, beryllium, heavy water, and light water are used)
4. A coolant to remove the fission-generated heat (water, sodium, helium, and nitrogen may be used)
5. A control system such as rods of boron or cadmium that have high capture cross sections (to absorb neutrons)
6. Adequate shielding, remote-control equipment, and appropriate instrumentation are essential for personnel safety and efficient operation.

omega-3 fatty acids    →   omega-3 masne kiseline

Omega-3 fatty acids are polyunsaturated fatty acids, meaning they contain more than one double bond. The name omega-3 indicates that the first double bond occurs on the third carbon atom (n-3) from the methyl (-CH₃) end of the molecule (omega position). The three main omega-3 fatty acids are alpha-linolenic acid (ALA, 18:3n-3), eicosapentaenoic acid (EPA, 20:5n-3), and docosahexaenoic acid (DHA, 22:6n-3). ALA comes from plants. EPA and DHA come from fish.

Similarly, the first double bond in omega-6 fatty acids is located between the sixth and seventh carbon atom (n-6) from the methyl end of the fatty acid (omega end).

ortho position    →   ortho položaj

Ortho position in organic chemistry is the one in which there are two same functional groups, tied to a ring of benzene in the positions 1 and 2. The abbreviation o- is used, for example, o-Hydroquinone is 1,2-dihydroxybenzene.

osmium    →   osmij

Osmium was discovered by Smithson Tennant (England) in 1803. The origin of the name comes from the Greek word osme meaning smell. It is hard fine black powder or hard, lustrous, blue-white metal. Unaffected by air, water and acids. Characteristic acrid, chlorine like odour due to tetroxide compound. Osmium tetroxide highly toxic. Osmium is obtained from the same ores as platinum. Used to tip gold pen points, instrument pivots, to make electric light filaments. Used for high temperature alloys and pressure bearings. Very hard and resists corrosion better than any other.