User talk:Electromagnet150

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Hi! I'm electromagnet150. I'm interested in physics and chemistry. I like dealing with thermal physics, nuclear physics, and electricity. There may still be things on chemistry and physics I might not know, but I'll learn more on my favorite subjects.

When you're in the physics or chemistry section, you'll use tons of symbols and units. Here are some units you might find a lot in the two sectors:

kJ/mol- Used for measuring gibbs free energies, enthalpies, electron affinities, etc.

kg/m3- SI unit for density.

Ω- SI unit for electrical resistance. Metals' resistivities are often measured in hundred-millionths of an ohm meter. Resistivities can also be measured by mill-ohm cm or ohm-meters.

Pa- SI unit for stress and pressure. Gigapascals, GPa, are used for measuring elastic moduli.

μ- this symbol can mean micro- (0.000001) or amperes per square meter, used to measure magnetic moment in NMR.

N- SI unit for force. Defined as one kg moving at 1 m/s.

K- SI unit for thermodynamic temperature (273 K MP, 373 K BP [water]). Subtract 273 to convert to Celsius.

Some well-known elements

Copper- Copper is a reddish brown metal. It is the second-best heat and electrical conductor of all metals (400 watts per meter Kelvin thermal conductivity and about 1.7 hundred-millionths of an Ω m) after silver. Copper (II) compounds have a characteristic blue color. Copper is used for making coins and electrical wires and many other things. Best-known compounds: CuSO4, CuCl2, CuO, Cu2S

Silver- Silver is the best heat conductor and electrical conductor of all metals (430 watts per meter Kelvin and about 1.6 hundred-millionths of an Ω m).Though silver is too expensive for making wires, it is used for making some electronics. Silver has the highest luster of all metals. It is attacked by H2SO4, HNO3, and sulfur compounds. Like copper and gold, silver is used for coins, but this use has almost ceased. Silver is used a lot for making eating utensils, mirror coatings, photographic films, dental fillings, jewelry. Best-known compounds: AgBr, AgNO3, AgI, AgCl, Ag2S

Gold- Gold is highly prized since ancient times. It is used for making coins, jewelry, dental fillings, and plating computer chips. The alchemists regarded gold as the perfect form of matter. Gold is attacked only by aqua regia (HNO3-HCl). Gold is a good thermal and electrical conductor. Alchemy was based on transmuting common metals into gold. Gold has the highest ductility and malleability of all metals. Best known compound: HAuCl6

Uranium- Uranium is a steel-gray, radioactive metal. It is a source of nuclear energy. Uranium's long half-lives make it weakly radioactive compared to other radioactive elements, but its decay products can be extremely radioactive indeed. Uranium hexaflouride (UF6) is the form of uranium delivered to power plants, and U-235 is the isotope suitable for nuclear fission. Uranium compounds give glass a translucent green color. Uranium has a lot of minerals, uranium minerals also contain small amounts of several other elements, most of them radioactive. Best-known compounds: UF6, U3O8

Cobalt- Cobalt is a bluish, ferromagnetic metal with a higher Curie point than iron. Though carcinogenic, cobalt is nutritious to several species, including humans, in the form of vitamin B12. Cobalt gives glass a blue color. Cobalt-60, with a half-life of a few years, has almost replaced radon gas entirely for cancer therapy. It emits γ rays but it can also emit β- particles to form Ni-60. Cobalt is used to make alnico, a strongly ferromagnetic alloy composed of aluminum, nickel,cobalt. Best known compounds: None Iron- Iron is the most common of all metals. Tools of the Iron Age were much stronger than previous bronze ones. They were also more durable. Iron is usually mixed with carbon to form steel, which is tougher than pure iron and more durable. Steel is used for almost every application, from railroad tracks to bridges and skyscrapers. There is still one drawback: Iron rusts, or corrodes, in moist air. So does steel. Therefore, iron and steel must be protected by the addition of corrosion resistant metals, such as zinc coating, or by painting them. Stainless steel, with chromium and nickel added, is corrosion resistant but expensive. Iron has probably the most alloys of any metal, as the most used metal. Best known compounds: Fe2O3.xH2O

Chlorine- Chlorine is a well-known, toxic gas. The gas irritates the mucus membranes and the liquid burns skin. It has a pale yellow color. The use of chlorine and other toxic gases by the Germans in WWI caused many deaths and polluted the battlefields of northern France. Poison gases and various other chemicals in warfare have been banned. Because of its toxicity, chlorine is an excellent disinfectant, and is used to clean pools. Chlorine compounds with the other halogens and hysdrogen are corrosive and toxic. Best known compounds: NaCl, CuCl2, CsCl, HCl, etc.