In chemistry, a metal (Greek: Metallon) is defined as an element that readily loses electrons to form positive ions (cations) and forms metallic bonds between other metal atoms[1] (forming ionic bonds with non-metals). Greek (el ελληνική γλώσσα or simply el ελληνικά — "Hellenic" is an Indo-European language, spoken today by 15-22 million people mainly A chemical element is a type of Atom that is distinguished by its Atomic number; that is by the number of Protons in its nucleus. An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge Although the term metallic bond is often used in contrast to the term Covalent bond it is better to speak of metallic bonding, because this type of bonding is An ionic bond (or electrovalent bond) is a type of Chemical bond that can often form between Metal and Non-metal Ions (or
Definition
The metals of the periodic table are formally defined as Lithium, beryllium, sodium, magnesium, aluminium, potassium, calcium, scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, gallium, rubidium, strontium, yttrium, zirconium, niobium, molybdenum, technetium, ruthenium, rhodium, palladium, silver, cadmium, indium, tin, antimony, caesium, barium, lanthanum, hafnium, tantalum, tungsten, rhenium, osmium, iridium, platinum, gold, mercury, thallium, lead, and bismuth. Lithium (ˈlɪθiəm is a Chemical element with the symbol Li and Atomic number 3 Beryllium (bəˈrɪliəm is a Chemical element with the symbol Be and Atomic number 4 Sodium (ˈsoʊdiəm is an element which has the symbol Na( Latin natrium, from Arabic natrun) atomic number 11 atomic mass 22 Magnesium (mægˈniːziəm is a Chemical element with the symbol Mg, Atomic number 12 Atomic weight 24 WikipediaNaming Potassium (pəˈtæsiəm is a Chemical element. It has the symbol K (kalium from qalīy Atomic number 19 and Atomic mass 39 Calcium (ˈkælsiəm is the Chemical element with the symbol Ca and Atomic number 20 Scandium (ˈskændiəm is a Chemical element that has the symbol Sc and Atomic number 21 Titanium (taɪˈteɪniəm is a Chemical element with the symbol Ti and Atomic number 22 Vanadium (vəˈneɪdiəm is a Chemical element that has the symbol V and Atomic number 23 Chromium (ˈkroʊmiəm is a Chemical element which has the symbol Cr and Atomic number 24 Manganese (ˈmæŋgəniːz is a Chemical element, designated by the symbol Mn. Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 Cobalt (ˈkoʊbɒlt is a hard lustrous silver-grey Metal, a Chemical element with symbol Co. Nickel (ˈnɪkəl is a metallic Chemical element with the symbol Ni and Atomic number 28 Copper (ˈkɒpɚ is a Chemical element with the symbol Cu (cuprum and Atomic number 29 Zinc (ˈzɪŋk from Zink is a Metallic Chemical element with the symbol Zn and Atomic number 30 Gallium (ˈgæliəm is a Chemical element that has the symbol Ga and Atomic number 31 Rubidium (ruːˈbɪdiəm /rəˈbɪdiəm/ is a Chemical element with the symbol Rb and Atomic number 37 Strontium (ˈstrɒntiəm /ˈstrɒnʃiəm/) is a Chemical element with the symbol Sr and the Atomic number 38 Yttrium (ˈɪtriəm is a Chemical element with symbol Y and Atomic number 39 Zirconium (zɚˈkoʊniəm /ˌzɝˈkoʊniəm/ is a Chemical element with the symbol Zr and Atomic number 40 Niobium (naɪˈoʊbiəm or columbium (/kəˈlʌmbiəm/ is a Chemical element that has the symbol Nb and Atomic number 41 Molybdenum (məˈlɪbdənəm from the Greek word for the metal " Lead " is a Group 6 Chemical element with the symbol Mo Technetium (tɛkˈniːʃɪəm is the lightest Chemical element with no Stable isotope. Ruthenium (ruːˈθiːniəm is a Chemical element that has the symbol Ru and Atomic number 44 Rh redirects here For other uses see Rh (disambiguation Rhodium (ˈroʊdiəm is a Chemical element with the symbol Palladium (pronounced \pəˈleɪdiəm\ is a rare and lustrous silvery-white metal that was discovered in 1803 by William Hyde Wollaston, who named it palladium after the Silver (ˈsɪlvɚ is a Chemical element with the symbol " Ag " (argentum from the Ancient Greek: ἀργήντος - argēntos gen Cadmium (ˈkædmiəm is a Chemical element with the symbol Cd and Atomic number 48 Indium (ˈɪndiəm is a Chemical element with chemical symbol In and Atomic number 49 Tin is a Chemical element with the symbol Sn (stannum and Atomic number 50 Antimony (IPA (Received Pronunciation, /ˈæntɪmoʊni/ (US is a Chemical element with the symbol Sb (stibium meaning "mark" and Caesium or cesium (ˈsiːziəm is the Chemical element with the symbol Cs and Atomic number 55 Barium (ˈbɛəriəm is a Chemical element. It has the symbol Ba, and Atomic number 56 Lanthanum (ˈlænθənəm is a Chemical element with the symbol La and Atomic number 57 Hafnium (ˈhæfniəm is a Chemical element that has the symbol Hf and Atomic number 72 Tantalum (ˈtæntələm (formerly tantalium /tænˈtæliəm/ is a Chemical element with the symbol Ta and Atomic number 73 Tungsten (ˈtʌŋstən also known as wolfram (/ˈwʊlfrəm/ is a Chemical element that has the symbol W and Atomic number 74 Rhenium (ˈriːniəm is a Chemical element with the symbol Re and Atomic number 75 Osmium (ˈɒzmiəm is a Chemical element that has the symbol Os and Atomic number 76 Iridium (ɪˈrɪdiəm is a Chemical element that has the symbol Ir and Atomic number 77 Platinum (ˈplætɪnəm is a Chemical element with the Atomic symbol Pt and an Atomic number of 78 Gold (ˈɡoʊld is a Chemical element with the symbol Au (from its Latin name aurum) and Atomic number 79 Mercury (ˈmɜrkjʊri also called quicksilver or hydrargyrum, is a Chemical element with the symbol Hg ( Latinized hydrargyrum Thallium (ˈθæliəm is a Chemical element with the symbol Tl and Atomic number 81 Characteristics Lead has a dull luster and is a dense, Ductile, very soft highly Bismuth (ˈbɪzməθ is a Chemical element that has the symbol Bi and Atomic number 83 [1] Metals are sometimes described as a lattice of positive ions surrounded by a cloud of delocalized electrons. In Mineralogy and Crystallography, a crystal structure is a unique arrangement of Atoms in a Crystal. The electron is a fundamental Subatomic particle that was identified and assigned the negative charge in 1897 by J are one of the three groups of elements as distinguished by their ionization and bonding properties, along with the metalloids and nonmetals. Metalloid is a term used in Chemistry when classifying the Chemical elements On the basis of their general physical and chemical properties nearly every element Nonmetal is a term used in Chemistry when classifying the Chemical elements On the basis of their general physical and chemical properties every element in the On the periodic table, a diagonal line drawn from boron (B) to polonium (Po) separates the metals from the nonmetals. Boron (ˈbɔərɒn is a Chemical element with Atomic number 5 and the chemical symbol B. Polonium (pəˈloʊniəm is a Chemical element with the symbol Po and Atomic number 84 discovered in 1898 by Marie and Pierre Curie Most elements on this line are metalloids, sometimes called semi-metals; elements to the lower left are metals; elements to the upper right are nonmetals (see the periodic table showing the metals). A semimetal is a material with a small overlap in the energy of the conduction band and Valence bands However the bottom of the conduction band is
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An alternative definition of metals is that they have overlapping conduction bands and valence bands in their electronic structure. In the Physics field of Semiconductors and insulators the conduction band is the range of Electron Energy, higher than that of the In Solids the valence band is the highest range of Electron energies where electrons are normally present at Absolute zero. This definition opens up the category for metallic polymers and other organic metals, which have been made by researchers and employed in high-tech devices. These synthetic materials often have the characteristic silvery-grey reflectiveness (luster) of elemental metals.
Chemical properties
Metals are usually inclined to form cations through electron loss,[1] reacting with oxygen in the air to form oxides over changing timescales (iron rusts over years, while potassium burns in seconds). An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge An oxide is a Chemical compound containing at least one Oxygen atom as well as at least one other element Rust is a general term for a series of Iron oxides, usually red oxides formed by the reaction of Iron with Oxygen in the presence of water or air Potassium (pəˈtæsiəm is a Chemical element. It has the symbol K (kalium from qalīy Atomic number 19 and Atomic mass 39 The alkali metals are the most volatile, followed by the alkaline earth metals, found in the leftmost two groups of the periodic table. Trends The alkali metals show a number of trends when moving down the group - for instance decreasing electronegativity increasing reactivity and decreasing melting and boiling Biological occurrences Beryllium's low aqueous solubility means it is rarely available to biological systems it has no known role in living organisms and when encountered The periodic table of the chemical elements is a tabular method of displaying the Chemical elements Although precursors to this table exist its invention is Examples:
- 4Na + O2 → 2Na2O (sodium oxide)
- 2Ca + O2 → 2CaO (calcium oxide)
- 4Al + 3O2 → 2Al2O3 (aluminium oxide)
The transition metals (such as iron, copper, zinc, and nickel) take much longer to oxidize. In Chemistry, the term transition metal (sometimes also called a transition element) has two possible meanings It commonly refers to any element in Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 Copper (ˈkɒpɚ is a Chemical element with the symbol Cu (cuprum and Atomic number 29 Zinc (ˈzɪŋk from Zink is a Metallic Chemical element with the symbol Zn and Atomic number 30 Nickel (ˈnɪkəl is a metallic Chemical element with the symbol Ni and Atomic number 28 Others, like palladium, platinum and gold, do not react with the atmosphere at all. Palladium (pronounced \pəˈleɪdiəm\ is a rare and lustrous silvery-white metal that was discovered in 1803 by William Hyde Wollaston, who named it palladium after the Platinum (ˈplætɪnəm is a Chemical element with the Atomic symbol Pt and an Atomic number of 78 Gold (ˈɡoʊld is a Chemical element with the symbol Au (from its Latin name aurum) and Atomic number 79 Some metals form a barrier layer of oxide on their surface which cannot be penetrated by further oxygen molecules and thus retain their shiny appearance and good conductivity for many decades (like aluminium, some steels, and titanium). An oxide is a Chemical compound containing at least one Oxygen atom as well as at least one other element WikipediaNaming Steel is an Alloy consisting mostly of Iron, with a Carbon content between 0 Titanium (taɪˈteɪniəm is a Chemical element with the symbol Ti and Atomic number 22 The oxides of metals are basic (as opposed to those of nonmetals, which are acidic), although this may be considered a rule of thumb, rather than a fact. An oxide is a Chemical compound containing at least one Oxygen atom as well as at least one other element In Chemistry, a base is most commonly thought of as an aqueous substance that can accept Protons This refers to the Brønsted-Lowry theory of acids and In Computer science, ACID ( Atomicity Consistency Isolation Durability) is a set of properties that guarantee that Database transactions are
Painting, anodising or plating metals are good ways to prevent their corrosion. Painting (pān'tīng in Art, is the practice of applying Color to a Surface (support base such as e Anodizing, or anodising, is an electrolytic Passivation process used to increase the thickness of the natural Oxide layer on the surface of metal Plating describes surface-covering where a Metal is deposited on a conductive surface Corrosion means the breaking down of essential properties in a material due to Chemical reactions with its surroundings However, a more reactive metal in the electrochemical series must be chosen for coating, especially when chipping of the coating is expected. The Standard electrode potentials are Electrode potentials of Half cells at equilibrium Water and the two metals form an electrochemical cell, and if the coating is less reactive than the coatee, the coating actually promotes corrosion. An electrochemical cell is a device used for generating an Electromotive force ( Voltage) and current from chemical reactions.
Physical properties
Metals in general have superior electric and thermal conductivity, high luster and density, and the ability to be deformed under stress without cleaving. Gallium (ˈgæliəm is a Chemical element that has the symbol Ga and Atomic number 31 Electrical conductivity or specific conductivity is a measure of a material's ability to conduct an Electric current. In Physics, thermal conductivity, k is the property of a material that indicates its ability to conduct Heat. Lustre (or luster) is a description of the way light interacts with the surface of a Crystal, rock, or Mineral. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different [1] While there are several metals that have low density, hardness, and melting points, these (the alkali and alkaline earth metals) are extremely reactive, and are rarely encountered in their elemental, metallic form[1]. Trends The alkali metals show a number of trends when moving down the group - for instance decreasing electronegativity increasing reactivity and decreasing melting and boiling Biological occurrences Beryllium's low aqueous solubility means it is rarely available to biological systems it has no known role in living organisms and when encountered
Density
The majority of metals have higher densities than the majority of nonmetals[1]. Nonetheless, there is wide variation in the densities of metals; lithium is the least dense solid element and osmium is the densest. Lithium (ˈlɪθiəm is a Chemical element with the symbol Li and Atomic number 3 Osmium (ˈɒzmiəm is a Chemical element that has the symbol Os and Atomic number 76 The metals of groups I A and II A are referred to as the light metals because they are exceptions to this generalization[1]. Light metals are Metals of low Atomic weight. The cut off between light metals and Heavy metals varies The high density of most metals is due to the tightly-packed crystal lattice of the metallic structure. The strength of metallic bonds for different metals reaches a maximum around the center of the transition series, as those elements have large amounts of delocalized electrons in a metallic bond. However, other factors (such as atomic radius, nuclear charge, number of bonding orbitals, overlap of orbital energies, and crystal form) are involved as well. Atomic radius, and more generally the size of an atom, is not a precisely defined Physical quantity, nor is it constant in all circumstances See also List of elements by atomic number In Chemistry and Physics, the atomic number (also known as the proton [1]
Malleability
The nondirectional nature of metallic bonding is thought to be the primary reason for the malleability of metal. Planes of atoms in a metal are able to slide across one another under stress, accounting for the ability of a crystal to deform without shattering.
When the planes of an ionic bond are slid past one another, the resultant change in location shifts ions of the same charge into close proximity, resulting in the cleavage of the crystal. An ionic bond (or electrovalent bond) is a type of Chemical bond that can often form between Metal and Non-metal Ions (or Covalently bonded crystals can only be deformed by breaking the bonds between atoms, thereby resulting in fragmentation of the crystal.
Conductivity
The electrical and thermal conductivity of metals originate from the fact that in the metallic bond, the outer electrons of the metal atoms form a gas of nearly free electrons, moving as an electron gas in a background of positive charge formed by the ion cores. Although the term metallic bond is often used in contrast to the term Covalent bond it is better to speak of metallic bonding, because this type of bonding is History See also Atomic theory, Atomism The concept that matter is composed of discrete units and cannot be divided into arbitrarily tiny Good mathematical predictions for electrical conductivity, as well as the electrons' contribution to the heat capacity and heat conductivity of metals can be calculated from the free electron model, which does not take the detailed structure of the ion lattice into account. In Solid-state physics, the free electron model is a simple model for the behaviour of Valence electrons in a Crystal structure of a Metallic
Electric charge
When considering the exact band structure and binding energy of a metal, it is necessary to take into account the positive potential caused by the specific arrangement of the ion cores - which is periodic in crystals. In Materials science, a crystal is a Solid in which the constituent Atoms Molecules or Ions are packed in a regularly ordered repeating The most important consequence of the periodic potential is the formation of a small band gap at the boundary of the brillouin zone. In Solid state physics and related applied fields a band gap, also called an energy gap or bandgap, is an energy range in a solid where no electron states In Mathematics and Solid state physics, the first Brillouin zone is a uniquely defined Primitive cell of the Reciprocal lattice in the Mathematically, the potential of the ion cores is treated in the nearly-free electron model. In Solid-state physics, the nearly free electron model is a model of electron behavior in solids that enables understanding the Electronic band structure of Crystalline
Alloys
An alloy is a mixture of two or more elements in solid solution in which the major component is a metal. An alloy is a Solid solution or Homogeneous mixture of two or more elements, at least one of which is a Metal, which itself has A chemical element is a type of Atom that is distinguished by its Atomic number; that is by the number of Protons in its nucleus. A solid solution is a Solid - state Solution of one or more solutes in a Solvent. Most pure metals are either too soft, brittle or chemically reactive for practical use. Combining different ratios of metals as alloys modifies the properties of pure metals to produce desirable characteristics. The aim of making alloys is generally to make them less brittle, harder, resistant to corrosion, or have a more desirable color and luster. Examples of alloys are steel (iron and carbon), brass (copper and zinc), bronze (copper and tin), and duralumin (aluminium and copper). Steel is an Alloy consisting mostly of Iron, with a Carbon content between 0 Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 Brass is any Alloy of Copper and Zinc; the proportions of zinc and copper can be varied to create a range of brasses with varying properties Copper (ˈkɒpɚ is a Chemical element with the symbol Cu (cuprum and Atomic number 29 Zinc (ˈzɪŋk from Zink is a Metallic Chemical element with the symbol Zn and Atomic number 30 Bronze is any of a broad range of Copper alloys, usually with Tin as the main additive but sometimes with other elements such as Phosphorus Copper (ˈkɒpɚ is a Chemical element with the symbol Cu (cuprum and Atomic number 29 Tin is a Chemical element with the symbol Sn (stannum and Atomic number 50 Duralumin (also called duraluminum, duraluminium or dural) is the trade name of one of the earliest types of age-hardenable Aluminium alloys WikipediaNaming Copper (ˈkɒpɚ is a Chemical element with the symbol Cu (cuprum and Atomic number 29 Alloys specially designed for highly demanding applications, such as jet engines, may contain more than ten elements. specific --->A jet engine is a Reaction engine that discharges a fast moving jet of Fluid to
Categories
Base metal
In chemistry, the term 'base metal' is used informally to refer to a metal that oxidizes or corrodes relatively easily, and reacts variably with dilute hydrochloric acid (HCl) to form hydrogen. In Chemistry, the term base metal is used informally to refer to a Metal that oxidizes or corrodes relatively easily and reacts variably with Chemistry (from Egyptian kēme (chem meaning "earth") is the Science concerned with the composition structure and properties Redox (shorthand for reduction-oxidation reaction describes all Chemical reactions in which atoms have their Oxidation number ( Oxidation state Corrosion means the breaking down of essential properties in a material due to Chemical reactions with its surroundings Hydrochloric acid is the Solution of Hydrogen chloride ( H[[Chlorine Cl]] in water Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Examples include iron, nickel, lead and zinc. Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 Nickel (ˈnɪkəl is a metallic Chemical element with the symbol Ni and Atomic number 28 Characteristics Lead has a dull luster and is a dense, Ductile, very soft highly Zinc (ˈzɪŋk from Zink is a Metallic Chemical element with the symbol Zn and Atomic number 30 Copper is considered a base metal as it oxidizes relatively easily, although it does not react with HCl. Copper (ˈkɒpɚ is a Chemical element with the symbol Cu (cuprum and Atomic number 29 It is commonly used in opposition to noble metal. Noble metals are Metals that are resistant to Corrosion or Oxidation, unlike most Base metals They tend to be Precious metals often
In alchemy, a base metal was a common and inexpensive metal, as opposed to precious metals, mainly gold and silver. Alchemy a part of the Occult Tradition is both a philosophy and a practice with an ultimately unknown aim involving the improvement of the alchemist as well as the making of Precious Metal is the eighteenth episode in the of the popular American Crime drama, which is set in Las Vegas, Nevada. Gold (ˈɡoʊld is a Chemical element with the symbol Au (from its Latin name aurum) and Atomic number 79 Silver (ˈsɪlvɚ is a Chemical element with the symbol " Ag " (argentum from the Ancient Greek: ἀργήντος - argēntos gen A longtime goal of the alchemists was the transmutation of base metals into precious metals.
In numismatics, coins used to derive their value primarily from the precious metal content. Numismatics (numisma nomisma "coin" from the νομίζειν nomízein, "to use according to law" is the study or collection of Currency Precious Metal is the eighteenth episode in the of the popular American Crime drama, which is set in Las Vegas, Nevada. Most modern currencies are fiat currency, allowing the coins to be made of base metal. The terms fiat currency and fiat money relate to types of currency or Money whose usefulness results not from any intrinsic value or guarantee that it can be
Ferrous metal
The term "ferrous" is derived from the latin word meaning "containing iron". Ferrous, in the chemical science realm indicates a bivalent iron compound (+2 oxidation state (as opposed to Ferric, which indicates a trivalent iron compound (+3 oxidation Latin ( lingua Latīna, laˈtiːna is an Italic language, historically spoken in Latium and Ancient Rome. This can include pure iron, such as wrought iron, or an alloy such as steel. QtubIronPillarJPG|thumb|right| Iron pillar at Delhi India containing 98% wrought iron]] Wrought iron is commercially pure Iron. Steel is an Alloy consisting mostly of Iron, with a Carbon content between 0 Ferrous metals are often magnetic, but not exclusively. In Physics, magnetism is one of the Phenomena by which Materials exert attractive or repulsive Forces on other Materials.
Noble metal
Noble metals are metals that are resistant to corrosion or oxidation, unlike most base metals. Noble metals are Metals that are resistant to Corrosion or Oxidation, unlike most Base metals They tend to be Precious metals often Corrosion means the breaking down of essential properties in a material due to Chemical reactions with its surroundings Redox (shorthand for reduction-oxidation reaction describes all Chemical reactions in which atoms have their Oxidation number ( Oxidation state In Chemistry, the term base metal is used informally to refer to a Metal that oxidizes or corrodes relatively easily and reacts variably with They tend to be precious metals, often due to perceived rarity. Examples include tantalum, gold, platinum, and rhodium. Tantalum (ˈtæntələm (formerly tantalium /tænˈtæliəm/ is a Chemical element with the symbol Ta and Atomic number 73 Gold (ˈɡoʊld is a Chemical element with the symbol Au (from its Latin name aurum) and Atomic number 79 Platinum (ˈplætɪnəm is a Chemical element with the Atomic symbol Pt and an Atomic number of 78 Rh redirects here For other uses see Rh (disambiguation Rhodium (ˈroʊdiəm is a Chemical element with the symbol
Precious metal
A precious metal is a rare metallic chemical element of high economic value. Precious Metal is the eighteenth episode in the of the popular American Crime drama, which is set in Las Vegas, Nevada. Gold (ˈɡoʊld is a Chemical element with the symbol Au (from its Latin name aurum) and Atomic number 79 A chemical element is a type of Atom that is distinguished by its Atomic number; that is by the number of Protons in its nucleus. An economy is the realized social system of production exchange distribution and consumption of goods and services of a country or other area
Chemically, the precious metals are less reactive than most elements, have high luster and high electrical conductivity. Lustre (or luster) is a description of the way light interacts with the surface of a Crystal, rock, or Mineral. Historically, precious metals were important as currency, but are now regarded mainly as investment and industrial commodities. A currency is a unit of exchange, facilitating the transfer of Goods and/or services It is one form of Money, where money is A commodity is anything for which there is demand but which is supplied without qualitative differentiation across a market Gold, silver, platinum and palladium each have an ISO 4217 currency code. Gold (ˈɡoʊld is a Chemical element with the symbol Au (from its Latin name aurum) and Atomic number 79 Silver (ˈsɪlvɚ is a Chemical element with the symbol " Ag " (argentum from the Ancient Greek: ἀργήντος - argēntos gen Platinum (ˈplætɪnəm is a Chemical element with the Atomic symbol Pt and an Atomic number of 78 Palladium (pronounced \pəˈleɪdiəm\ is a rare and lustrous silvery-white metal that was discovered in 1803 by William Hyde Wollaston, who named it palladium after the ISO 4217 is the International standard describing three-letter codes (also known as the currency code) to define the names of currencies established The best-known precious metals are gold and silver. While both have industrial uses, they are better known for their uses in art, jewelry, and coinage. Art refers to a diverse range of Human activities creations and expressions that are appealing to the Senses or Emotions of a human individual Jewellery (also spelled jewelry, see spelling differences) is a personal Ornament, such as a necklace ring or bracelet made from Gemstones A currency is a unit of exchange, facilitating the transfer of Goods and/or services It is one form of Money, where money is Other precious metals include the platinum group metals: ruthenium, rhodium, palladium, osmium, iridium, and platinum, of which platinum is the most widely traded. The platinum group (alternatively the platinum group metals or platinum metals) is a collective name sometimes used for six Metallic elements Ruthenium (ruːˈθiːniəm is a Chemical element that has the symbol Ru and Atomic number 44 Rh redirects here For other uses see Rh (disambiguation Rhodium (ˈroʊdiəm is a Chemical element with the symbol Palladium (pronounced \pəˈleɪdiəm\ is a rare and lustrous silvery-white metal that was discovered in 1803 by William Hyde Wollaston, who named it palladium after the Osmium (ˈɒzmiəm is a Chemical element that has the symbol Os and Atomic number 76 Iridium (ɪˈrɪdiəm is a Chemical element that has the symbol Ir and Atomic number 77 Platinum (ˈplætɪnəm is a Chemical element with the Atomic symbol Pt and an Atomic number of 78 Plutonium and uranium could also be considered precious metals. Uranium (jʊˈreɪniəm is a silvery-gray Metallic Chemical element in the
The demand for precious metals is driven not only by their practical use, but also by their role as investments and a store of value. To act as a store of value, a Commodity, a form of Money, or Financial capital must be able to be reliably saved stored and retrieved - and be predictably Palladium was, as of summer 2006, valued at a little under half the price of gold, and platinum at around twice that of gold. Silver is substantially less expensive than these metals, but is often traditionally considered a precious metal for its role in coinage and jewelry.
Extraction
Metals are often extracted from the Earth by means of mining, resulting in ores that are relatively rich sources of the requisite elements. An ore is a volume of rock containing components or Minerals in a mode of occurrence that renders it valuable for mining Mining is the extraction of valuable Minerals or other geological materials from the earth usually (but not always from an Ore body Ore is located by prospecting techniques, followed by the exploration and examination of deposits. Prospecting is the physical search for Minerals Fossils precious metals or mineral specimens and is also known as Fossicking. Mineral sources are generally divided into surface mines, which are mined by excavation using heavy equipment, and subsurface mines. Surface mining is a type of Mining in which soil and rock overlying the mineral deposit are removed
Once the ore is mined, the metals must be extracted, usually by chemical or electrolytic reduction. Extractive Metallurgy is the practice of extracting Metal from Ore, purifying it and recycling it Pyrometallurgy uses high temperatures to convert ore into raw metals, while hydrometallurgy employs aqueous chemistry for the same purpose. Pyrometallurgy is a branch of Extractive metallurgy. It consists of the thermal treatment of minerals and metallurgical ores and concentrates to bring about physical and chemical Hydrometallurgy is part of the field of Extractive metallurgy involving the use of Aqueous chemistry for the recovery of metals from ores concentrates and recycled The methods used depend on the metal and their contaminants.
Metallurgy
Metallurgy is a domain of materials science that studies the physical and chemical behavior of metallic elements, their intermetallic compounds, and their mixtures, which are called alloys. Metallurgy is a domain of Materials science that studies the physical and chemical behavior of metallic elements, their intermetallic compounds, and their
Applications
Some metals and metal alloys possess high structural strength per unit mass, making them useful materials for carrying large loads or resisting impact damage. Metal alloys can be engineered to have high resistance to shear, torque and deformation. However the same metal can also be vulnerable to fatigue damage through repeated use, or from sudden stress failure when a load capacity is exceeded. The strength and resilience of metals has led to their frequent use in high-rise building and bridge construction, as well as most vehicles, many appliances, tools, pipes, non-illuminated signs and railroad tracks.
The two most commonly used structural metals, iron and aluminium, are also the most abundant metals in the Earth's crust. Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 WikipediaNaming In Geology, a crust is the outermost solid shell of a planet or moon [2]
Metals are good conductors, making them valuable in electrical appliances and for carrying an electric current over a distance with little energy lost. Electrical power grids rely on metal cables to distribute electricity. Home electrical systems, for the most part, are wired with copper wire for its good conducting properties.
The thermal conductivity of metal is useful for containers to heat materials over a flame. Metal is also used for heat sinks to protect sensitive equipment from overheating. A heat sink (or heatsink) is an environment or object that absorbs and dissipates heat from another object using Thermal contact (either direct or radiant
The high reflectivity of some metals is important in the construction of mirrors, including precision astronomical instruments. This last property can also make metallic jewelry aesthetically appealing.
Some metals have specialized uses; Radioactive metals such as Uranium and Plutonium are used in nuclear power plants to produce energy via nuclear fission. Uranium (jʊˈreɪniəm is a silvery-gray Metallic Chemical element in the This article is a subarticle of Nuclear power. A nuclear reactor is a device in which Nuclear chain reactions are initiated controlled Nuclear fission is the splitting of the nucleus of an atom into parts (lighter nuclei) often producing Free neutrons and other smaller nuclei which may Mercury is a liquid at room temperature and is used in switches to complete a circuit when it flows over the switch contacts. Shape memory alloy is used for applications such as pipes, fasteners and vascular stents. A shape memory alloy (SMA also known as a smart alloy, memory metal, or muscle wire) is an Alloy that "remembers" its shape In Medicine, a stent is a tube that is inserted into a natural conduit of the body to prevent or counteract a disease-induced localized flow constriction However they are very good at conducting electricity and heat.
Trade
The World Bank reports that China was the top importer of ores and metals in 2005 followed by the U. An ore is a volume of rock containing components or Minerals in a mode of occurrence that renders it valuable for mining The World Bank is an internationally supported Bank that provides financial and technical assistance to developing countries for development programs (e An ore is a volume of rock containing components or Minerals in a mode of occurrence that renders it valuable for mining S. A. and Japan.
Astronomy
In the specialised usage of astronomy and astrophysics, the term "metal" is often used to refer to any element other than hydrogen or helium, including substances as chemically non-metallic as neon, fluorine, and oxygen. In Astronomy and Physical cosmology, the metallicity of an object is the proportion of its matter made up of Chemical elements other than Hydrogen Astronomy (from the Greek words astron (ἄστρον "star" and nomos (νόμος "law" is the scientific study Astrophysics is the branch of Astronomy that deals with the Physics of the Universe, including the physical properties ( Luminosity, Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Helium ( He) is a colorless odorless tasteless non-toxic Inert Monatomic Chemical Neon (ˈniːɒn is the Chemical element that has the symbol Ne and Atomic number 10 Fluorine, fluorum meaning "to flow" is the Chemical element with the symbol F and Atomic number 9 Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the Nearly all the hydrogen and helium in the Universe was created in Big Bang nucleosynthesis, whereas all the "metals" were produced by nucleosynthesis in stars or supernovae. The Universe is defined as everything that Physically Exists: the entirety of Space and Time, all forms of Matter, Energy In Physical cosmology, Big Bang nucleosynthesis (or primordial nucleosynthesis) refers to the production of nuclei other than those of H-1 (i Nucleosynthesis is the process of creating new atomic nuclei from preexisting Nucleons (protons and neutrons A star is a massive luminous ball of plasma. The nearest star to Earth is the Sun, which is the source of most of the Energy on Earth Supernova nucleosynthesis is the production of new Chemical elements inside Supernovae It occurs primarily due to explosive Nucleosynthesis during explosive The Sun and the Milky Way Galaxy are composed of roughly 70% hydrogen, 30% helium, and 2% "metals" by mass. The Sun (Sol is the Star at the center of the Solar System. The Milky Way (a translation of the Latin Via Lactea, in turn derived from the Greek Γαλαξίας (Galaxias sometimes referred to simply [3]
See also
References
- ^ a b c d e f g h Mortimer, Charles E. ASM International formerly known as the American Society for Metals is a Professional organization for materials scientists and engineers working with An amorphous metal is a Metallic material with a disordered atomic-scale structure Screening is the damping of Electric fields caused by the presence of mobile charge carriers Metalworking is craft and practice of working with Metals to create individual parts assemblies or large scale structures Although the term metallic bond is often used in contrast to the term Covalent bond it is better to speak of metallic bonding, because this type of bonding is Metallurgy is a domain of Materials science that studies the physical and chemical behavior of metallic elements, their intermetallic compounds, and their Steel is an Alloy consisting mostly of Iron, with a Carbon content between 0 Structural steel is Steel construction Material, a profile, formed with a specific Shape or cross section and certain standards of In Chemistry, the term transition metal (sometimes also called a transition element) has two possible meanings It commonly refers to any element in Chemistry: A Conceptual Approach. 3rd ed. New York: D. Van Nostrad Company, 1975.
- ^ Frank Kreith and Yogi Goswami, eds. (2004). The CRC Handbook of Mechanical Engineering, 2nd edition. CRC: Boca Raton. p. 12-2.
- ^ Sparke, Linda S. & Gallagher, John S. (2000), Galaxies in the Universe (1 ed. John (Jay S Gallagher III is currently a Professor of Astronomy at the University of Wisconsin-Madison andthe Editor of the Astronomical Journal. ), Cambridge University Press, pp. 8, ISBN 0521592410
External links
Dictionary
metal
-noun
- Any of a number of chemical elements in the periodic table that form a metallic bond with other metal atoms; generally shiny, somewhat malleable and hard, often a conductor of heat and electricity.
- Any material with similar physical properties, such as an alloy.
- (astronomy) Any element other than hydrogen and helium,<ref>Majewski, S. R. (2003, 2006). CHEMICAL ABUNDANCE EFFECTS ON SPECTRAL ENERGY DISTRIBUTIONS. ASTR 551 (Majewski) Lecture Notes.</ref> or sometimes other than hydrogen.<ref>Martin, J. C. (n.d.). What we learn from a star's metal content</ref>
- Crushed rock, stones etc. used to make a road.
- (heraldry) A light tincture used in a coat of arms, specifically argent and or.
- Molten glass that is to be blown or moulded to form objects
- A category of rock music encompassing a number of genres (including thrash metal, death metal, heavy metal, etc.) categorised by strong and/or fast drum-beats and distorted guitars.
-adjective
- Made of metal.
- Of or pertaining to the metal musical genre (e.g. the metal scene).
-verb
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