Elements (CONT'D)

7/29/2019 Elements (CONT'D)

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Iron

Iron is a chemical element with the symbol Fe (from Latin:ferrum) and atomic number26. It is

a metal in the first transition series. It is the most common element (by mass) forming the planet

Earth as a whole, forming much of Earth's outerand inner core. It is the fourth most common

element in the Earth's crust. Iron's very common presence in rocky planets like Earth is due to its

abundant production as a result of fusion in high-mass stars, where the production ofnickel-56

(which decays to the most common isotope of iron) is the last nuclear fusion reaction that is

exothermic. This causes radioactive nickel to become the last element to be produced before

collapse of a supernova leads to the explosive events that scatter this precursorradionuclide of

iron abundantly into space.Iron metal has been used since ancient times, though copper alloys,

which have lower melting temperatures, were used first in history. Pure iron is soft (softer than

aluminium), but is unobtainable by smelting. The material is significantly hardened and

strengthened by impurities from the smelting process, such as carbon. A certain proportion of

carbon (between 0.2% and 2.1%) produces steel, which may be up to 1000 times harder thanpure iron. Crude iron metal is produced in blast furnaces, where ore is reduced by coke to pig

iron, which has a high carbon content. Further refinement with oxygen reduces the carbon

content to the correct proportion to make steel. Steels and low carbon iron alloys with other

metals (alloy steels) are by far the most common metals in industrial use, due to their great range

of desirable properties and the abundance of iron.
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Nickel

Nickel is a chemical element with the chemical symbol Ni and atomic number28. It is a silvery-

white lustrous metal with a slight golden tinge. Nickel belongs to the transition metals and is

hard and ductile. Pure nickel shows a significant chemical activity that can be observed when

nickel is powdered to maximize the exposed surface area on which reactions can occur, butlarger pieces of the metal are slow to react with air at ambient conditions due to the formation of

a protective oxide surface. Even then, nickel is reactive enough with oxygen so that native nickel

is rarely found on Earth's surface, being mostly confined to the interiors of largernickeliron

meteorites that were protected from oxidation during their time in space. On Earth, such native

nickel is always found in combination with iron, a reflection of those elements' origin as major

end products ofsupernova nucleosynthesis. An ironnickel mixture is thought to compose

Earth's inner core.The use of nickel (as a natural meteoric nickeliron alloy) has been traced as

far back as 3500 BC. Nickel was first isolated and classified as a chemical element in 1751 by

Axel Fredrik Cronstedt, who initially mistook its ore for a copper mineral. The element name

comes from a mischievous sprite of German miner's mythology, Nickel (similar to Old Nick),that personified the fact that copper-nickel ores resisted refinement into copper. An economically

important source of nickel is the iron ore limonite, which often contains 1-2% nickel. Nickel's

other important ore minerals include garnierite, and pentlandite. Major production sites include

Sudbury region in Canada (which is thought to be of meteoric origin), New Caledonia in the

Pacific and Norilskin Russia.
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Potassium

Potassium is a chemical element with symbol K(from Neo-Latin kalium) and atomic number19.

Elemental potassium is a soft silvery-white alkali metal that oxidizes rapidly in airand is very

reactive with water, generating sufficient heat to ignite the hydrogen emitted in the reaction and

burning with a lilac flame.

Because potassium and sodium are chemically very similar, theirsalts were not at firstdifferentiated. The existence of multiple elements in their salts was suspected from 1702,

[1]and

this was proven in 1807 when potassium and sodium were individually isolated from different

salts by electrolysis. Potassium in nature occurs only in ionic salts. As such, it is found dissolved

in seawater(which is 0.04% potassium by weight[2][3]

), and is part of many minerals.

Most industrial chemical applications of potassium employ the relatively high solubility in waterof potassium compounds, such as potassium soaps. Potassium metal has only a few special

applications, being replaced in most chemical reactions with sodium metal.

Potassium ions are necessary for the function of all living cells. Potassium ion diffusion is a keymechanism in nerve transmission, and potassium depletion in animals, including humans, results

in various cardiac dysfunctions. Potassium accumulates in plant cells, and thus fresh fruits and

vegetables are a good dietary source of it. Conversely, most plants except specialist halophytesare intolerant of salt, and sodium is present in them only in low concentration. This resulted in

potassium first being isolated from potash, the ashes of plants, giving the element its name. For

the same reason, heavy crop production rapidly depletes soils of potassium, and agriculturalfertilizers consume 95% of global potassium chemical production.

[
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Calcium

Calcium is the chemical element with symbol Ca and atomic number20. Calcium is a soft grayalkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust. Calcium

is also the fifth-most-abundant dissolved ion in seawaterby both molarity and mass, aftersodium,

chloride, magnesium, and sulfate.[2]

Calcium is essential for living organisms, in particular in cell physiology, where movement of

the calcium ion Ca2+

into and out of the cytoplasm functions as a signal for many cellularprocesses. As a major material used in mineralization ofbone, teeth and shells, calcium is the

most abundant metalby mass in many animals.
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Magnesium

Magnesium is a chemical element with symbol Mg and atomic number12. Its common

oxidation number is +2. It is an alkaline earth metal and the eighth most abundant element in the

Earth's crust[2]

and ninth in the known universe as a whole.[3][4]

Magnesium is the fourth most

common element in the Earth as a whole (behind iron, oxygen and silicon), making up 13% ofthe planet's mass and a large fraction of the planet's mantle. The relative abundance of

magnesium is related to the fact that it is easily built up in supernova stars from a sequential

addition of three helium nuclei to carbon (which in turn is made from three helium nuclei). Due

to magnesium ion's high solubility in water, it is the third most abundant element dissolved inseawater.

In human biology, magnesium is the eleventh most abundant element by mass in the human body;its ions are essential to all living cells, where they play a major role in manipulating important

biological polyphosphate compounds like ATP, DNA, and RNA. Hundreds ofenzymes thus

require magnesium ions to function. Magnesium compounds are used medicinally as commonlaxatives, antacids (e.g., milk of magnesia), and in a number of situations where stabilization of
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abnormal nerve excitation and blood vessel spasm is required (e.g., to treat eclampsia).

Magnesium ions are sour to the taste, and in low concentrations they help to impart a natural

tartness to fresh mineral waters.

In vegetation magnesium is the metallic ion at the center ofchlorophyll, and is thus a common

additive to fertilizers.

[6]

Sodium

Sodium is a chemical element with the symbol Na (from Latin:natrium) in the periodic table

and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the

alkali metals; its only stable isotope is23Na. The free metal does not occur in nature, but instead

must be prepared from its compounds; it was first isolated by Humphry Davy in 1807 by the

electrolysis ofsodium hydroxide. Sodium is the sixth most abundant element in the Earth's crust,

and exists in numerous minerals such as feldspars, sodalite and rock salt. Many salts of sodiumare highly water-soluble, and their sodium has been leached by the action of water so thatchloride and sodium are the most common dissolved elements by weight in the Earth's bodies of

oceanic water.

Many sodium compounds are useful, such as sodium hydroxide (lye) forsoapmaking, and

sodium chloride for use as a deicing agent and a nutrient (edible salt). Sodium is an essential

element for all animals and some plants. In animals, sodium ions are used against potassium ions
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to build up charges on cell membranes, allowing transmission of nerve impulses when the charge

is dissipated. The consequent need of animals for sodium causes it to be classified as a dietary

inorganic macro-mineral

Nitrogen

Nitrogen is a chemical element with symbol N and atomic number7. Elemental nitrogen is a

colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting78.09% by volume ofEarth's atmosphere. The element nitrogen was discovered as a separable

component of air, by Scottish physician Daniel Rutherford, in 1772. It belongs to the pnictogen

family.

Nitrogen is a common element in the universe, estimated at about seventh in total abundance inourgalaxy and the Solar System. It is synthesised by fusion ofcarbon and hydrogen in

supernovas. Due to the volatility of elemental nitrogen and its common compounds withhydrogen and oxygen, nitrogen is far less common on the rocky planets of the inner Solar

System, and it is a relatively rare element on Earth as a whole. However, as on Earth, nitrogen

and its compounds occur commonly as gases in the atmospheres of planets and moons that haveatmospheres.
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Many industrially important compounds, such as ammonia, nitric acid, organic nitrates

(propellants and explosives), and cyanides, contain nitrogen. The extremely strong bond in

elemental nitrogen dominates nitrogen chemistry, causing difficulty for both organisms andindustry in converting (or "fixing") the N2 into useful compounds, but at the same time causing

release of large amounts of often useful energy when the compounds burn, explode, or decay

back into nitrogen gas. Synthetically-produced ammonia and nitrates are key industrial fertilizersand fertilizer nitrates are key pollutants in causing the eutrophication of water systems.

Hydrogen

Hydrogen is a chemical element with symbol H and atomic number1. With an atomic weight of

1.00794 u (1.007825 u forhydrogen-1), hydrogen is the lightest element and its monatomic form

(H1) is the most abundant chemical substance, constituting roughly 75% of the Universe's

baryonic mass.

[7]

Non-remnant stars are mainly composed of hydrogen in its plasma state.

At standard temperature and pressure, hydrogen is a colorless, odorless, tasteless, non-toxic,nonmetallic, highly combustible diatomic gas with the molecular formula H2. Naturally

occurring atomic hydrogen is rare on Earth because hydrogen readily forms covalent compounds

with most elements and is present in the water molecule and in most organic compounds.Hydrogen plays a particularly important role in acid-base chemistry with many reactions

exchanging protonsbetween soluble molecules.

In ionic compounds, it can take a negative charge (an anion known as a hydride and written as

H

), or as a positively charged species H+. The lattercation is written as though composed of a

bare proton, but in reality, hydrogen cations in ionic compounds always occur as more complexspecies.

The most common isotope of hydrogen is protium (name rarely used, symbol1H) with a single

proton and no neutrons. As the simplest atom known, the hydrogen atom has been of theoretical

use. For example, as the only neutral atom with an analytic solution to the Schrdinger equation,

the study of the energetics and bonding of the hydrogen atom played a key role in thedevelopment ofquantum mechanics.
http://en.wikipedia.org/wiki/Ammoniahttp://en.wikipedia.org/wiki/Nitric_acidhttp://en.wikipedia.org/wiki/Propellanthttp://en.wikipedia.org/wiki/Explosivehttp://en.wikipedia.org/wiki/Cyanidehttp://en.wikipedia.org/wiki/Chemical_compoundhttp://en.wikipedia.org/wiki/Ammoniahttp://en.wikipedia.org/wiki/Nitratehttp://en.wikipedia.org/wiki/Fertilizerhttp://en.wikipedia.org/wiki/Pollutanthttp://en.wikipedia.org/wiki/Eutrophicationhttp://en.wikipedia.org/wiki/Chemical_elementhttp://en.wikipedia.org/wiki/Chemical_symbolhttp://en.wikipedia.org/wiki/Atomic_numberhttp://en.wikipedia.org/wiki/Atomic_weighthttp://en.wikipedia.org/wiki/Atomic_mass_unithttp://en.wikipedia.org/wiki/Atomic_mass_unithttp://en.wikipedia.org/wiki/Hydrogen-1http://en.wikipedia.org/wiki/Abundance_of_the_chemical_elementshttp://en.wikipedia.org/wiki/Baryonhttp://en.wikipedia.org/wiki/Hydrogen#cite_note-7http://en.wikipedia.org/wiki/Hydrogen#cite_note-7http://en.wikipedia.org/wiki/Hydrogen#cite_note-7http://en.wikipedia.org/wiki/Stellar_remnanthttp://en.wikipedia.org/wiki/Starhttp://en.wikipedia.org/wiki/Plasma_%28physics%29http://en.wikipedia.org/wiki/Standard_temperature_and_pressurehttp://en.wikipedia.org/wiki/Transparency_%28optics%29http://en.wikipedia.org/wiki/Odorlesshttp://en.wikipedia.org/wiki/Tastehttp://en.wikipedia.org/wiki/Nonmetalhttp://en.wikipedia.org/wiki/Combustionhttp://en.wikipedia.org/wiki/Diatomic_moleculehttp://en.wikipedia.org/wiki/Gashttp://en.wikipedia.org/wiki/Molecular_formulahttp://en.wikipedia.org/wiki/Covalent_bondhttp://en.wikipedia.org/wiki/Organic_compoundhttp://en.wikipedia.org/wiki/Acid-base_reaction_theorieshttp://en.wikipedia.org/wiki/Protonhttp://en.wikipedia.org/wiki/Ionic_compoundhttp://en.wikipedia.org/wiki/Anionhttp://en.wikipedia.org/wiki/Hydridehttp://en.wikipedia.org/wiki/Chemical_specieshttp://en.wikipedia.org/wiki/Cationhttp://en.wikipedia.org/wiki/Ionic_compoundhttp://en.wikipedia.org/wiki/Isotopehttp://en.wikipedia.org/wiki/Hydrogen-1http://en.wikipedia.org/wiki/Neutronhttp://en.wikipedia.org/wiki/Hydrogen_atomhttp://en.wikipedia.org/wiki/Schr%C3%B6dinger_equationhttp://en.wikipedia.org/wiki/Quantum_mechanicshttp://en.wikipedia.org/wiki/Quantum_mechanicshttp://en.wikipedia.org/wiki/Schr%C3%B6dinger_equationhttp://en.wikipedia.org/wiki/Hydrogen_atomhttp://en.wikipedia.org/wiki/Neutronhttp://en.wikipedia.org/wiki/Hydrogen-1http://en.wikipedia.org/wiki/Isotopehttp://en.wikipedia.org/wiki/Ionic_compoundhttp://en.wikipedia.org/wiki/Cationhttp://en.wikipedia.org/wiki/Chemical_specieshttp://en.wikipedia.org/wiki/Hydridehttp://en.wikipedia.org/wiki/Anionhttp://en.wikipedia.org/wiki/Ionic_compoundhttp://en.wikipedia.org/wiki/Protonhttp://en.wikipedia.org/wiki/Acid-base_reaction_theorieshttp://en.wikipedia.org/wiki/Organic_compoundhttp://en.wikipedia.org/wiki/Covalent_bondhttp://en.wikipedia.org/wiki/Molecular_formulahttp://en.wikipedia.org/wiki/Gashttp://en.wikipedia.org/wiki/Diatomic_moleculehttp://en.wikipedia.org/wiki/Combustionhttp://en.wikipedia.org/wiki/Nonmetalhttp://en.wikipedia.org/wiki/Tastehttp://en.wikipedia.org/wiki/Odorlesshttp://en.wikipedia.org/wiki/Transparency_%28optics%29http://en.wikipedia.org/wiki/Standard_temperature_and_pressurehttp://en.wikipedia.org/wiki/Plasma_%28physics%29http://en.wikipedia.org/wiki/Starhttp://en.wikipedia.org/wiki/Stellar_remnanthttp://en.wikipedia.org/wiki/Hydrogen#cite_note-7http://en.wikipedia.org/wiki/Baryonhttp://en.wikipedia.org/wiki/Abundance_of_the_chemical_elementshttp://en.wikipedia.org/wiki/Hydrogen-1http://en.wikipedia.org/wiki/Atomic_mass_unithttp://en.wikipedia.org/wiki/Atomic_mass_unithttp://en.wikipedia.org/wiki/Atomic_weighthttp://en.wikipedia.org/wiki/Atomic_numberhttp://en.wikipedia.org/wiki/Chemical_symbolhttp://en.wikipedia.org/wiki/Chemical_elementhttp://en.wikipedia.org/wiki/Eutrophicationhttp://en.wikipedia.org/wiki/Pollutanthttp://en.wikipedia.org/wiki/Fertilizerhttp://en.wikipedia.org/wiki/Nitratehttp://en.wikipedia.org/wiki/Ammoniahttp://en.wikipedia.org/wiki/Chemical_compoundhttp://en.wikipedia.org/wiki/Cyanidehttp://en.wikipedia.org/wiki/Explosivehttp://en.wikipedia.org/wiki/Propellanthttp://en.wikipedia.org/wiki/Nitric_acidhttp://en.wikipedia.org/wiki/Ammonia


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Industrial production is mainly from the steam reforming of natural gas, and less often from

more energy-intensive hydrogen production methods like the electrolysis of water.[9]

Most

hydrogen is employed near its production site, with the two largest uses being fossil fuel

processing (e.g., hydrocracking) and ammoniaproduction, mostly for the fertilizer market.

Sodium

Sodium is a chemical element with the symbol Na (from Latin:natrium) in the periodic tableand atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the

alkali metals; its only stable isotope is23Na. The free metal does not occur in nature, but instead

must be prepared from its compounds; it was first isolated by Humphry Davy in 1807 by the

electrolysis ofsodium hydroxide. Sodium is the sixth most abundant element in the Earth's crust,and exists in numerous minerals such as feldspars, sodalite and rock salt. Many salts of sodium

are highly water-soluble, and their sodium has been leached by the action of water so thatchloride and sodium are the most common dissolved elements by weight in the Earth's bodies of

oceanic water.

Many sodium compounds are useful, such as sodium hydroxide (lye) forsoapmaking, and

sodium chloride for use as a deicing agent and a nutrient (edible salt). Sodium is an essential
http://en.wikipedia.org/wiki/Hydrogen_productionhttp://en.wikipedia.org/wiki/Electrolysis_of_waterhttp://en.wikipedia.org/wiki/Hydrogen#cite_note-9http://en.wikipedia.org/wiki/Hydrogen#cite_note-9http://en.wikipedia.org/wiki/Hydrogen#cite_note-9http://en.wikipedia.org/wiki/Fossil_fuelhttp://en.wikipedia.org/wiki/Hydrocrackinghttp://en.wikipedia.org/wiki/Ammoniahttp://en.wikipedia.org/wiki/Chemical_elementhttp://en.wikipedia.org/wiki/Latin_languagehttp://en.wikipedia.org/wiki/Alkali_metalshttp://en.wikipedia.org/wiki/Isotopehttp://en.wikipedia.org/wiki/Humphry_Davyhttp://en.wikipedia.org/wiki/Electrolysishttp://en.wikipedia.org/wiki/Sodium_hydroxidehttp://en.wikipedia.org/wiki/Abundance_of_elements_in_Earth%27s_crusthttp://en.wikipedia.org/wiki/Feldsparhttp://en.wikipedia.org/wiki/Sodalitehttp://en.wikipedia.org/wiki/Halitehttp://en.wikipedia.org/wiki/Sea_salthttp://en.wikipedia.org/wiki/Sea_waterhttp://en.wikipedia.org/wiki/Soaphttp://en.wikipedia.org/wiki/Sodium_chloridehttp://en.wikipedia.org/wiki/Edible_salthttp://en.wikipedia.org/wiki/Dietary_mineralhttp://en.wikipedia.org/wiki/Dietary_mineralhttp://en.wikipedia.org/wiki/Edible_salthttp://en.wikipedia.org/wiki/Sodium_chloridehttp://en.wikipedia.org/wiki/Soaphttp://en.wikipedia.org/wiki/Sea_waterhttp://en.wikipedia.org/wiki/Sea_salthttp://en.wikipedia.org/wiki/Halitehttp://en.wikipedia.org/wiki/Sodalitehttp://en.wikipedia.org/wiki/Feldsparhttp://en.wikipedia.org/wiki/Abundance_of_elements_in_Earth%27s_crusthttp://en.wikipedia.org/wiki/Sodium_hydroxidehttp://en.wikipedia.org/wiki/Electrolysishttp://en.wikipedia.org/wiki/Humphry_Davyhttp://en.wikipedia.org/wiki/Isotopehttp://en.wikipedia.org/wiki/Alkali_metalshttp://en.wikipedia.org/wiki/Latin_languagehttp://en.wikipedia.org/wiki/Chemical_elementhttp://en.wikipedia.org/wiki/Ammoniahttp://en.wikipedia.org/wiki/Hydrocrackinghttp://en.wikipedia.org/wiki/Fossil_fuelhttp://en.wikipedia.org/wiki/Hydrogen#cite_note-9http://en.wikipedia.org/wiki/Electrolysis_of_waterhttp://en.wikipedia.org/wiki/Hydrogen_production


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element for all animals and some plants. In animals, sodium ions are used against potassium ions

to build up charges on cell membranes, allowing transmission of nerve impulses when the charge

is dissipated. The consequent need of animals for sodium causes it to be classified as a dietaryinorganic macro-mineral.

Calcium

Calcium is the chemical element with symbol Ca and atomic number20. Calcium is a soft gray

alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust. Calcium

is also the fifth-most-abundant dissolved ion in seawaterby both molarity and mass, aftersodium,chloride, magnesium, and sulfate.

[2]

Calcium is essential for living organisms, in particular in cell physiology, where movement ofthe calcium ion Ca

2+into and out of the cytoplasm functions as a signal for many cellular

processes. As a major material used in mineralization ofbone, teeth and shells, calcium is the

most abundant metalby mass in many animals.
http://en.wikipedia.org/wiki/Dietary_mineralhttp://en.wikipedia.org/wiki/Potassiumhttp://en.wikipedia.org/wiki/Na%2B/K%2B-ATPasehttp://en.wikipedia.org/wiki/Chemical_elementhttp://en.wikipedia.org/wiki/Atomic_numberhttp://en.wikipedia.org/wiki/Alkaline_earth_metalhttp://en.wikipedia.org/wiki/Abundance_of_the_chemical_elementshttp://en.wikipedia.org/wiki/Earthhttp://en.wikipedia.org/wiki/Crust_%28geology%29http://en.wikipedia.org/wiki/Seawaterhttp://en.wikipedia.org/wiki/Sodiumhttp://en.wikipedia.org/wiki/Chloridehttp://en.wikipedia.org/wiki/Magnesiumhttp://en.wikipedia.org/wiki/Sulfatehttp://en.wikipedia.org/wiki/Calcium#cite_note-2http://en.wikipedia.org/wiki/Calcium#cite_note-2http://en.wikipedia.org/wiki/Calcium#cite_note-2http://en.wikipedia.org/wiki/Organismhttp://en.wikipedia.org/wiki/Cell_%28biology%29http://en.wikipedia.org/wiki/Physiologyhttp://en.wikipedia.org/wiki/Cytoplasmhttp://en.wikipedia.org/wiki/Bonehttp://en.wikipedia.org/wiki/Toothhttp://en.wikipedia.org/wiki/Exoskeletonhttp://en.wikipedia.org/wiki/Metalhttp://en.wikipedia.org/wiki/Animalhttp://en.wikipedia.org/wiki/Animalhttp://en.wikipedia.org/wiki/Metalhttp://en.wikipedia.org/wiki/Exoskeletonhttp://en.wikipedia.org/wiki/Toothhttp://en.wikipedia.org/wiki/Bonehttp://en.wikipedia.org/wiki/Cytoplasmhttp://en.wikipedia.org/wiki/Physiologyhttp://en.wikipedia.org/wiki/Cell_%28biology%29http://en.wikipedia.org/wiki/Organismhttp://en.wikipedia.org/wiki/Calcium#cite_note-2http://en.wikipedia.org/wiki/Sulfatehttp://en.wikipedia.org/wiki/Magnesiumhttp://en.wikipedia.org/wiki/Chloridehttp://en.wikipedia.org/wiki/Sodiumhttp://en.wikipedia.org/wiki/Seawaterhttp://en.wikipedia.org/wiki/Crust_%28geology%29http://en.wikipedia.org/wiki/Earthhttp://en.wikipedia.org/wiki/Abundance_of_the_chemical_elementshttp://en.wikipedia.org/wiki/Alkaline_earth_metalhttp://en.wikipedia.org/wiki/Atomic_numberhttp://en.wikipedia.org/wiki/Chemical_elementhttp://en.wikipedia.org/wiki/Na%2B/K%2B-ATPasehttp://en.wikipedia.org/wiki/Potassiumhttp://en.wikipedia.org/wiki/Dietary_mineral

Documents

Elements (CONT'D)