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Topic: Alkali metal

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  Alkali - Wikipedia, the free encyclopedia
In chemistry, an alkali (from Arabic: al-qaly) is a specific type of base, formed as a carbonate, hydroxide or other basic (pH greater than 7) ionic salt of an alkali metal or alkali earth metal element.
This definition of an alkali as a basic salt of an alkali metal or alkali earth metal does appear to be the most common, based on dictionary definitions [1][2], however conflicting definitions of the term alkali do exist.
In alkali lakes (a type of salt lake), evaporation concentrates the naturally occurring alkali salts, often forming a crust of mildly basic salt across a large area.
en.wikipedia.org /wiki/Alkali   (523 words)

 Alkali metal - Wikipedia, the free encyclopedia
The alkali metals are the series of elements in Group 1 (IUPAC style) of the periodic table (excluding hydrogen in all but one rare circumstance): lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr).
The alkali metals are silver-colored (caesium has a golden tinge), soft, low-density metals, which react readily with halogens to form ionic salts, and with water to form strongly alkaline (basic) hydroxides.
Alkali metals are famous for their vigorous reactions with water, and these reactions become increasingly violent as you move down the periods.
en.wikipedia.org /wiki/Alkali_metal   (510 words)

 Alkali metal - Simple English Wikipedia
Alkali metals are the chemical elements in group one of the periodic system.
Alkali metals are the first group in the periodic table.
Alkali metals are: Lithium (Li), Sodium (Na), Potassium (K), Rubidium (Rb), Cesium (Cs), and Francium (Fr).
simple.wikipedia.org /wiki/Alkali_metal   (247 words)

The alkali metals are so highly reactive that they never occur free (in their elemental form) in nature, but always in combination with other elements.
The vast majority of reactions of alkali metal compounds are acid-base reactions involving the anions associated with the alkali metals.
Alkali metals relatively large atomic size (radii) and single electron far from the nucleus, account for their low electron densities and hence low ionization energies.
intro.chem.okstate.edu /ChemSource/Alkalimetals/alkalimetals.html   (1168 words)

 Alkali metal: Facts and details from Encyclopedia Topic   (Site not responding. Last check: 2007-09-20)
In chemistry, a metal (greek: metallon) is an element that readily forms ions (cations) and has metallic bonds, and it is sometimes said that it is similar...
A hydride is a chemical compound or form of a bond between hydrogen with a metal usually found in group 1 of the periodic table, usually with a more electropositive...
Metallic hydrogen results when hydrogen is sufficiently compressed and undergoes a phase change, and it is an example of degenerate matter....
www.absoluteastronomy.com /encyclopedia/a/al/alkali_metal.htm   (890 words)

 [No title]   (Site not responding. Last check: 2007-09-20)
In the method of the invention, the alkali metal, alkaline earth metal, or combination thereof can be present in the catalyst either in a stoichiometric amount or in excess of a stoichiometric amount.
Alkali metal is defined as those metals listed in Group 1 (IA) of the Periodic Table of Elements, or a combination thereof.
However, the amount of alkali and/or alkaline earth metal in the catalyst should not exceed an amount where the pore space of the catalyst is significantly restricted, thereby decreasing the surface area of the catalyst and its activity.
www.wipo.int /cgi-pct/guest/getbykey5?KEY=01/56971.010809&ELEMENT_SET=DECL   (2571 words)

 Visual Elements: Group 1 - The Alkali Metals
The alkali metals are so reactive they cannot be displaced by another element, so are isolated by electrolysis of their molten salts.
Alkali metal hydroxides are white ionic crystalline solids of formula MOH, and are soluble in water.
Alkali metal halides are white ionic crystalline solids.
www.chemsoc.org /viselements/pages/data/intro_groupi_data.html   (841 words)

 Chapter 7, Section 6   (Site not responding. Last check: 2007-09-20)
Not surprisingly, the chemistry of the alkali metals is dominated by the formation of 1+ cations (Equation 7.16).
Alkali metal ions, having lost their outermost electrons, have no electrons that can be excited by visible radiation.
The alkali metal ions are reduced to gaseous metal atoms in the lower central region of the flame.
cwx.prenhall.com /bookbind/pubbooks/blb/chapter7/medialib/blb0706.html   (1321 words)

 Cesium - The Periodic Table of the Elements - Formation Inc. - The Information Corporation
Alkali metals themselves define the concept of metallic reactivity, by reacting violently with Water, with the evolution of Heat, Light and Hydrogen gas, a property important in Energy Conversion.
Alkali metals are thus generally quite soft and flammable, with increasing reactivity with increasing atomic weight, and, with the usual exception of Lithium, will ignite spontaneously in Air and Water.
Alkali metals, with a valence of +1, react directly with the halides to form ionic salts, which then can undergo Electrolysis at nearly 100% efficiency, and which dissociate back into their respective ions, when in Solution.
webpages.charter.net /cosmic/elements/cesium.htm   (338 words)

 Chemical Elements.com - Alkali Metals   (Site not responding. Last check: 2007-09-20)
The alkali metals, found in group 1 of the periodic table (formerly known as group IA), are very reactive metals that do not occur freely in nature.
As with all metals, the alkali metals are malleable, ductile, and are good conductors of heat and electricity.
Alkali metals can explode if they are exposed to water.
www.chemicalelements.com /groups/alkali.html   (108 words)

 [No title]   (Site not responding. Last check: 2007-09-20)
The organic salt is an alkali metal bound to a disubstituted amide of alkane iminosulfinic acid.
A method for forming an alkali disubstituted amide of alkane iminosulfinic acid salt includes the steps of providing disubstituted amides of alkane iminosulfinic acid, a source of alkali metal ions and at least one organic solvent, and mixing together the substituted alkane iminosulfinic acid, the source of alkali metal ions and the organic solvent.
In a preferred embodiment of the invention, the salt is an alkali metal bonded to an N, N'-disubstituted amide of pentane iminosulfinic acid.
www.wipo.int /cgi-pct/guest/getbykey5?KEY=03/90297.031030&ELEMENT_SET=DECL   (5279 words)

These characteristics lead to relatively weak attractions between the atoms in the alkali metals and the alkali metal ions in their compounds.
The large hydrated alkali metal ions have a very low tendency to function as acids by donating protons (from the H 2 O ligands).
[Alkali metals have large atomic radii and as a consequence the outer valence electron is only weakly attracted by the core charge of +1.
intro.chem.okstate.edu /ChemSource/Alkalimetals/alkmetals3a.htm   (599 words)

 The MSDS HyperGlossary: Alkali Metal
In their elemental forms, the alkali metals are all soft, ductile, malleable substances that can be easily cut with a knife or drawn into a wire.
Alkali metals are quite reactive towards air and water, with increasingly dangerous reactivity as one moves down the column from Li to Cs.
When working with alkali metals, be sure you have a fire extinguisher that is approved for Class D fires.
www.ilpi.com /msds/ref/alkalimetal.html   (640 words)

 Interpretation   (Site not responding. Last check: 2007-09-20)
Sodium metal oxidizes rapidly in moist air at room temperature, but spontaneous ignitions have not been reported except when the sodium is in a finely divided form or when it is mixed with an incompatible material (i.e., water, oxidizing agents, halogenated hydrocarbons, halogens, or sulfuric acid).
It is a good practice to store empty as well as filled alkali metal containers in the same area, and all containers should be on skids.
Ventilation at a high spot in the room is desirable to vent any hydrogen that may be released by accidental contact of alkali metal with moisture.
www.eh.doe.gov /il/unpres/d95-06-065.htm   (567 words)

Alkali metals have the property of being very reactive in an air environment.
If any alkali metal carbonate residue is observed, it will be removed using a wet rag and brush that will not scratch the stainless steel surface.
Note: Action levels for the alkali metal carbonates as derived from the equivalent concentration criteria (WAC 173-303-100) for characteristic Category D (least toxic) dangerous waste is 10 percent weight of contaminated material.
www.hanford.gov /docs/rl-91-35/rl91-357.htm   (2219 words)

 Untitled Document   (Site not responding. Last check: 2007-09-20)
In this reaction, the alkali metal strips halogen from the metal halide.
The metal is then free to grow into a thin film on a substrate placed in the reaction zone.
Metal nitride or metal oxide ceramic films are easily formed by the introduction of nitrogen or oxygen gases into the reactor.
www.nist.gov /sigmaxi/Posters98/abs/Hendricks.html   (383 words)

 General Chemistry Online: Glossary: The periodic table
The radius of atoms obtained from covalent bond lengths is called the covalent radius; the radius from interatomic distances in metallic crystals is called the metallic radius.
As a consequence, sixth period transition metals are about the same size as their fifth period counterparts.
A metal is a substance that conducts heat and electricity, is shiny and reflects many colors of light, and can be hammered into sheets or drawn into wire.
antoine.frostburg.edu /chem/senese/101/periodic/glossary.shtml   (597 words)

 Results in
Vapors of alkali metals (most commonly, cesium or rubidium, both of which melt at temperatures slightly above room temperature) are needed for atomic frequency standards, experiments in spectroscopy, and experiments in laser cooling.
Initially, the vessel is evacuated, the alkali metal charge is distilled into the bottom of the vessel, and then the fill tube is pinched closed to form a vacuum seal.
In the event (unlikely in normal Earth gravitation) that any drops of molten alkali metal have been shaken loose by vibration and are floating freely, a mesh cap on top of the inner cylinder prevents the drops from drifting out with the vapor.
www.findarticles.com /p/articles/mi_qa3957/is_200511/ai_n15846216   (343 words)

 Lithium and Other Alkali Metal Use   (Site not responding. Last check: 2007-09-20)
However, the recent fire has pointed out that in small-scale experiments conducted by researchers or assistants who have not worked extensively with alkali metals, inadvertent mishandling of gram quantities of lithium (or sodium) may represent an underappreciated hazard.
Unfortunately, we have no way of identifying who is using "borrowed" alkali metals except through the owners from whom they are obtained.
If your lab is currently lending or borrowing small quantities of alkali metals or has in the recent past, I would appreciate your assistance in identifying experiments which are currently using them, so that we can offer the researchers safety consulting on an individualized basis.
eetd.lbl.gov /EHS/Lessons/LithiumFire.html   (253 words)

 alkali   (Site not responding. Last check: 2007-09-20)
Description: Lithium, sodium, and potassium metals are sliced and then a small sample of each is reacted with water.
Concept: The alkali metals are soft and silvery.
Make sure all the metal you added got to react and, when it has, the remaining water and hydroxide can be washed down the drain.
chemlearn.chem.indiana.edu /demos/Alkali.htm   (225 words)

 SAES Getters - Alkali Metal Dispensers - AMDs
Alkali Metal Dispensers (AMDs) are compact sources of alkali metals.
The alkali metal generating source is a mixture of an alkali metal chromate with a reducing agent.
In addition to reducing the alkali back to its metallic state, St101 also removes chemically reactive gases from the device, preventing them from contaminating the alkali metal vapor.
www.saesgetters.com /default.aspx?idPage=470   (174 words)

 Metalworking @ MetalworkArt.com (Metalwork Art)   (Site not responding. Last check: 2007-09-20)
Milling is generally done on a milling machine, which is a power-driven machine used for the complex shaping of metal (or possibly other materials) parts, by removing unneeded material to form the final shape.
In a metalworking lathe, metal is removed from the workpiece using a hardened cutting tool which is usually fixed to a solid moveable mounting called the "toolpost", this arrangement is then moved around the workpiece using handwheels and/or computer controlled motors.
This is often done by melting the workpieces and adding a filler material to form a pool of molten material that cools to become a strong joint, but sometimes pressure is used in conjunction with heat, or by itself, to produce the weld.
www.metalworkart.com   (2132 words)

 Alkali Metals   (Site not responding. Last check: 2007-09-20)
Group I of the Periodic Table is composed of highly reactive metals.
Alkali metals tend to lose one electron and form ions with a single positive charge.
They form ionic compounds (salts) in reaction with the halogens (alkali halides).
hyperphysics.phy-astr.gsu.edu /hbase/pertab/alkmet.html   (105 words)

 Learn more about Alkali metal in the online encyclopedia.   (Site not responding. Last check: 2007-09-20)
Hydrogen, with a solitary electron, nominally belongs in the alkali metals group.
However, removal of that single electron requires considerably more energy than for the other alkali metals.
In the form of metallic hydrogen, however, it behaves more as an alkali metal.
www.onlineencyclopedia.org /a/al/alkali_metal.html   (221 words)

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