potassium

(pətăs`ēəm), a metallic chemical element; symbol K [Lat. kalium=alkali]; at. no. 19; at. wt. 39.0983; m.p. 63.25&degC;; b.p. 760&degC;; sp. gr. .862 at 20&degC;; valence +1.

Potassium is a soft, silver-white metal. Physically and chemically it resembles the other alkali metalsalkali metals,
metals found in Group 1 of the periodic table. Compared to other metals they are soft and have low melting points and densities. Alkali metals are powerful reducing agents and form univalent compounds.
..... Click the link for more information. in Group 1 of the periodic tableperiodic table,
chart of the elements arranged according to the periodic law discovered by Dmitri I. Mendeleev and revised by Henry G. J. Moseley. In the periodic table the elements are arranged in columns and rows according to increasing atomic number (see the table entitled
..... Click the link for more information. . It is extremely reactive, more so than sodium. It combines so readily with oxygen that it is usually stored submerged in kerosene or some other hydrocarbon, out of contact with air. It reacts violently with water to form potassium hydroxide, KOH, releasing hydrogen, which usually ignites. It combines directly with the halogens, sulfur, and other nonmetallic elements (except nitrogen). It reacts with many organic compounds.

The metal has limited use since it so closely resembles sodium, which is readily available at lower cost. Nonetheless, potassium compounds are widely used in industry, although they are usually more expensive than the similar sodium compound. Potassium carbonatepotassium carbonate,
chemical compound, K₂CO₃, white, crystalline, deliquescent substance that forms a strongly alkaline water solution. It is available commercially as a white, granular powder commonly called potash, or pearl ash.
..... Click the link for more information. , or potash, K₂CO₃, is used principally in soap and glass manufacture. The chloride, KCl, is used in fertilizers and in the production of other potassium compounds. The chlorate, KClO₃, and perchlorate, KClO₄, are used in explosives and fireworks. The hydroxide, or caustic potash, KOH, is used in soaps. The nitrate, saltpeter (or niter), KNO₃, is used in matches and explosives. Other commercially useful compounds include the bromide, KBr, the cyanide, KCN, the chromate, K₂CrO₄, the dichromate, K₂Cr₂O₇, and the iodide, KI.

Javelle waterJavelle water
or Javel water
, Fr. eau de Javelle, aqueous solution of sodium or potassium hypochlorite. It was originally made near the French town of Javelle (now part of Paris) and was the first chemical bleach, a use first demonstrated by C. L.
..... Click the link for more information. contains potassium hypochlorite, KClO, a compound found only in solution. The metasilicate, K₂SiO₃, is used in water glasswater glass
or soluble glass,
colorless, transparent, glasslike substance available commercially as a powder or as a transparent, viscous solution in water. Chemically it is sodium silicate, potassium silicate, or a mixture of these.
..... Click the link for more information. . Potassium has several useful tartaric acid salts, e.g., Rochelle saltRochelle salt,
colorless to blue-white orthorhombic crystalline salt with a saline, cooling taste. It is also called Seignette salt after Pierre Seignette, an apothecary of La Rochelle, France, who was the first to make it (c.1675).
..... Click the link for more information. (sodium potassium tartrate), tartartartar
or argol
, impure potassium hydrogen tartrate deposited as a crust in fermenting vessels during wine making. When purified, it yields cream of tartar. Tartar is the chief natural source of tartaric acid.
..... Click the link for more information. (argol) and cream of tartarcream of tartar,
white crystalline powder. Chemically it is potassium hydrogen tartrate, KC₄H₅O₆, the acidic potassium salt of tartaric acid. It is used as the leavening agent in baking powders.
..... Click the link for more information. (potassium hydrogen tartrate), and tartar emetictartar emetic,
poisonous, odorless, transparent rhombic crystals or white powder with a metallic, sweetish taste. Chemically, it is potassium antimony tartrate, KSbC₄H₄O₇· 1-2H₂O. It is used as a mordant in dyeing.
..... Click the link for more information. (potassium antimony tartrate). Potassium aluminum sulfate, KAl(SO₄)₂·12H₂O, is a compound used in tanning, in water purification, and in baking powder; usually called alumalum
, any one of a series of isomorphous double salts that are hydrated sulfates of a univalent cation (e.g., potassium, sodium, ammonium, cesium, or thallium) and a trivalent cation (e.g., aluminum, chromium, iron, manganese, cobalt, or titanium).
..... Click the link for more information. , it is also called potash alum to distinguish it from other alkali aluminum sulfates. Potassium permanganate, KMnO₄, a purple-black, crystalline compound that forms deep purple, aqueous solutions, is used in the chemical laboratory as a powerful oxidizing agent and in medicine as an antiseptic and disinfectant.

With sodium the metal forms alloys that are liquid at room temperature; these alloys are sometimes used in chemical reactions. Substances containing potassium impart a purple color to a flame. Potassium does not occur uncombined in nature but is found widely distributed in sylvite (KCl), carnallite (MgCl₂·KCl), feldspar, mica, and other minerals. It is the seventh most abundant element in the earth's crust and the sixth most abundant of the elements in solution in the oceans. It is found in mineral waters, brines, and salt deposits. Potassium is an essential nutrient for plants and animals.

Potassium metal is produced commercially by a thermochemical process in which molten potassium chloride is reacted with sodium vapor; this method is also used to produce liquid sodium-potassium alloys. The metal may be produced electrolytically from fused potassium hydroxide, but, unlike sodium and lithium, it reacts with carbon electrodes and may form explosive compounds. Potassium was discovered in 1807 by Humphry DavyDavy, Sir Humphry,
1778–1829, English chemist and physicist. The son of a woodcarver, he received his early education at Truro and was apprenticed (1795) to a surgeon-apothecary at Penzance.
..... Click the link for more information. , who decomposed potash with an electric current. Potassium was the first metal so discovered; Davy discovered sodium a few days later by a similar experiment.

potassium

[pə′tas·ē·əm] (chemistry) A chemical element, symbol K, atomic number 19, atomic weight 39.0983; an alkali metal. Also known as kalium.

potassium

a light silvery element of the alkali metal group that is highly reactive and rapidly oxidizes in air; occurs principally in carnallite and sylvite. It is used when alloyed with sodium as a cooling medium in nuclear reactors and its compounds are widely used, esp in fertilizers. Symbol: K; atomic no.: 19; atomic wt.: 39.0983; valency: 1; relative density: 0.862; melting pt.: 63.71°C; boiling pt.: 759°C

potassium

(K) [po-tas´e-um] a chemical element, atomic number 19, atomic weight 39.102. (See Appendix 6.) In combination with other minerals in the body, potassium forms alkaline salts that are important in body processes and play an essential role in maintenance of the acid-base and water balance in the body. All body cells, especially muscle tissue, require a high content of potassium. A proper balance between sodium, calcium, and potassium in the blood plasma is necessary for proper cardiac function.
Since most foods contain a good supply of potassium, potassium deficiency (hypokalemia) is unlikely to be caused by an unbalanced diet. Possible causes include cushing's syndrome (due to an adrenal gland disorder) and fanconi's syndrome (the result of a congenital kidney defect). The cause could also be an excessive dose of cortisone, prolonged vomiting or diarrhea, or thiazide diuretics, which are administered for treatment of hypertension. Signs of potassium deficiency can include weakness and lethargy, rapid pulse, nausea, diarrhea, and tingling sensations.
If the body absorbs enough potassium but the element is not distributed properly, various disorders may develop. Thus an abnormally low content of potassium in the blood may result in an intermittent temporary paralysis of the muscles, known as paralysis" >familial periodic paralysis.
Potassium deficiency can be treated by administration of potassium supplements. There is a large variety of these preparations. Some are liquids, some are powders to be dissolved in liquids, and some are slow-release tablets that dissolve in the intestine. All can cause gastrointestinal irritation. For many persons on diuretic therapy for hypertension, potassium deficiency can be avoided by increasing their consumption of potassium-containing foods, such as bananas, dates, prunes, and raisins, and potassium supplements are not needed. Potassium supplements are never given to patients receiving potassium-sparing diuretics such as amiloride, spironolactone, or triamterene. If the difficulty lies in the body's use of potassium, treatment is concerned with the primary cause of the deficiency.

Homeostatic balance of potassium. Through the functions of resorption and excretion, the kidneys are the best regulator of potassium balance in the extracellular fluids. From Malarkey and McMorrow, 2000.potassium acetate an electrolyte replenisher and systemic and urinary alkalizer.potassium bicarbonate an electrolyte replenisher, antacid, and urinary alkalizer.potassium bitartrate a compound administered rectally as a suppository with sodium bicarbonate to produce carbon dioxide, which promotes defecation by distending the rectal ampulla; administered for relief of constipation, and evacuation of the colon before surgical or diagnostic procedures or childbirth.potassium chloride a compound used orally or intravenously as an electrolyte replenisher.potassium citrate a systemic and urinary alkalizer, electrolyte replenisher, and diuretic.dibasic potassium phosphate the dipotassium salt, K₂HPO₄; used alone or in combination with other phosphate compounds as an electrolyte replenisher.potassium gluconate an electrolyte replenisher used in the prophylaxis and treatment of hypokalemia.potassium guaiacolsulfonate an expectorant.potassium iodide an expectorant, antithyroid agent, and antifungal.monobasic potassium phosphate the monopotassium salt, KH₂PO₄; used as a buffering agent in pharmaceutical preparations and, alone or in combination with other phosphate compounds, as an electrolyte replenisher and urinary acidifier and for prevention of kidney stones.potassium permanganate a topical antiinfective and oxidizing agent, and an antidote for many poisons.potassium phosphate a compound combining potassium and phosphoric acid, usually dibasic potassium phosphate.potassium sodium tartrate a compound used as a saline cathartic.

po·tas·si·um (K),

(pō-tas'ē-ŭm), An alkaline metallic element, atomic no. 19, atomic wt. 39.0983, occurring abundantly in nature but always in combination; its salts are used medicinally. For organic potassium salts not listed below, see the name of the anion. Synonym(s): kalium [Mod. L., fr. Eng. potash (fr. pot + ashes) + -ium]

potassium

An alkaline metallic element (atomic number 19; atomic weight 39.09), potassium is the principal intracellular cation (positive ion) and is critical in the synthesis of new molecules, transferring energy, muscle contraction, transmitting neural impulses and maintaining blood pressure. Potassium-rich foods include bananas, cereals, legumes, potatoes, prunes and raisins.

potassium

K+, Kalium Physiology An alkaline metallic element–atomic number 19; atomic weight 39.09; it is the principal intracellular cation–positive ion and is critical for synthesis of new molecules, transfer of energy, muscle contraction, neural transmission, and maintaining BP; K+ in the circulation has a narrow range; it is ↓ in crash dieting, Cushing syndrome, DKA, dehydration, hyperaldosteronism, licorice–due to aldosterone-like effects of glycerrhizic acid, malnutrition, metabolic acidosis, nasogastic suctioning, starvation, stress–burns, surgery, trauma, vomiting, and drugs–eg, aspirin, corticosteroids, potassium-wasting diuretics, estrogen, insulin, laxatives, lithium, sodium polystyrene sulfonate–Kaylexate; it is ↑ with anuria or oliguria, tissue injury/necrosis, burns, potassium in IV solutions, metabolic acidosis, renal insufficiency or failure, and therapy with K+-sparing diuretics–eg, spironolactone, antibiotics–eg, cephalosporins, isoniazid, penicillin, epinephrine, histamine Potassium-rich foods Bananas, cereals, legumes, potatoes, prunes, raisins

po·tas·si·um

(K) (pŏ-tas'ē-ŭm) An alkaline metallic element, atomic no. 19, atomic wt. 39.0983, occurring abundantly in nature but always in combination; its salts are used medicinally; the primary intracellular cation.
Synonym(s): kalium. [Mod. L., fr. Eng. potash (fr. pot + ashes) + -ium]

potassium

An important body mineral present in carefully controlled concentration. Potassium is necessary for normal heart rhythm, for the regulation of the body's water balance and for the conduction of nerve impulses and the contraction of muscles. Many diuretic drugs result in a loss of potassium from the body and this can be dangerous. Supplementary potassium is often included in the formulation of these preparations. Potassium may also be given as a separate supplement in such preparations as Kay-Cee-L or Slow-K.

Potassium

A mineral found in whole grains, meat, legumes, and some fruits and vegetables. Potassium is important for many body processes, including proper functioning of the nerves and muscles.Mentioned in: Diuretics, Hypokalemia

po·tas·si·um

(pŏ-tas'ē-ŭm) An alkaline metallic element, occurring abundantly in nature but always in combination; its salts are used medicinally. [Mod. L., fr. Eng. potash (fr. pot + ashes) + -ium]

potassium

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potassium

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potassium

potassium

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potassium

po·tas·si·um (K),

potassium

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Synonyms for potassium

noun a light soft silver-white metallic element of the alkali metal group

Synonyms

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