D elements are called the transition elements. The atoms of these elements have valence electrons i

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D elements are called the transition elements. The atoms of these elements have valence electrons in orbitals and hb (n-1) 1 through 10 wherein n is the number of periods catalyst consulting group 4-7. They have some common features in the Niel groups (eg, in skuoine chromium and copper) but also in codorovných ranks.
A) d all elements are metals. The atomic radii are relatively less than in the elements. On the metallic bond valence electrons are involved mainly of incompletely filled d orbitals. Transition metals are therefore particularly high density, high boiling point. They are usually hard, excel mechanical strength, especially in alloys.
B) atoms in compounds having different oxidation numbers whereas the valence electrons have about the same energy and the formation of bonds may be in addition to electrons n, to be used also. Exceptions are zinc, Cadmium and Mercury. A closed configuration of n-1D10 which are minimally involved in metal binding. Mercury has a particularly low melting point (-38.9 C). Transition catalyst consulting group metals are term thermal and electrical conductor catalyst consulting group (silver, gold and copper)
C) ions and compounds are colored because by absorbing visible light to transfer power between neighboring levels. Only ions with empty orbitálmy d ..... or completely filled catalyst consulting group d orbitálmy. For example, Cu +, Ag + Zn 2+ are colorless.
Transition catalyst consulting group metals on the order of scandium iron never occur in nature mainly in the compounds with oxygen. On the order of iron to zinc as sulphides particular. Gold and platinum are poorly reactive (noble gases) therefore occur in unadulterated form or in alloys. Production of metals from ores is engaged in metallurgy.
Occurrence and importance 4th most abundant element in the earth's crust after (letter). With nickel forms the core of the Earth is part of the meteorites, it jajdôležitejší technical metal found in organisms in hemoglobin as Fe2 +. Foods with a higher content of iron are: red meat, legumes etc. Najznámejšiw iron ore are: magnetite, magnetite Fe3O4; hematite, Fe2O3 krveľ; limonite, brown Fe2O3.nH2O; pirit FeS2; chalkopirit CuFeS2; siderite, FeCO3 ocielok. Slovakia catalyst consulting group is the only usable iron ore siderite, 11% of domestic consumption, occurs mainly in the Slovak Ore Mountains. Iron is produced in a blast furnace. How vzádzka used coke, a flux limestone. Blast furnace operates continuously for years. Hot metal is deleted every 4 to 6 hours. Products blast furnace - slag -Raw iron -vysokopecný gas (CO) Triad Iron - Fe, Co, Ni - vysíkej iron from the furnace is hard, strong, malleable and fragile, easily corrodes - surface corrosion 2 Fe + nH2O + 3O2 = (2FeO3.nH2O) - accelerate corrosion of minerals dissolved in water, for example. NaClm carbon dioxide, air humidity, and acidic environment. Protection: Oil, painting, enamelling, plating
Steel, features serious production - it nakpoužívanejší construction catalyst consulting group materials - - carbon content of less than 2 percent - is obtained skkujňovaním pig iron (reduced content of undesirable elements mainly carbon and adding features that improve the quality of steel, its essence is the reaction catalyst consulting group of pig iron with oxygen, which is injected catalyst consulting group under pressure and with impurities, gaseous nitrogen, which leak out) the process is carried out in converters. The converter is added to pig iron and scrap. PODS method of cooling the steel is divided into: - hardened (rapid cooling, extremely strong but brittle) - tempered (gradual cooling, less brittle)
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