Crossword clues for potassium
Longman Dictionary of Contemporary English
The Collaborative International Dictionary
Potassium \Po*tas"si*um\, n. [NL. See Potassa, Potash.] (Chem.) An Alkali element, occurring abundantly but always combined, as in the chloride, sulphate, carbonate, or silicate, in the minerals sylvite, kainite, orthoclase, muscovite, etc. Atomic weight 39.0. Symbol K (Kalium).
Note: It is reduced from the carbonate as a soft white metal, lighter than water, which oxidizes with the greatest readiness, and, to be preserved, must be kept under liquid hydrocarbons, as naphtha or kerosene. Its compounds are very important, being used in glass making, soap making, in fertilizers, and in many drugs and chemicals.
Potassium permanganate, the salt KMnO4, crystallizing in dark red prisms having a greenish surface color, and dissolving in water with a beautiful purple red color; -- used as an oxidizer and disinfectant. The name chameleon mineral is applied to this salt and also to potassium manganate.
Potassium bitartrate. See Cream of tartar, under Cream.
Douglas Harper's Etymology Dictionary
n. A soft, waxy, silvery reactive metal that is never found unbound in nature; an element (''symbol'' K) with an atomic number of 19 and atomic weight of 39.0983. The symbol is derived from the Latin ''kalium''.
n. a light soft silver-white metallic element of the alkali metal group; oxidizes rapidly in air and reacts violently with water; is abundant in nature in combined forms occurring in sea water and in carnallite and kainite and sylvite [syn: K, atomic number 19]
Potassium is a chemical element with symbol K (derived from Neo-Latin, kalium) and atomic number 19. It was first isolated from potash, the ashes of plants, from which its name derives. In the Periodic table, potassium is one of seven elements in column (group) 1 ( alkali metals). All elements in Group 1 have a single valence electron in the outer electron shell, which is easily removed to create an ion with a positive charge – a cation, which combines with anions to form salts. Potassium in nature occurs only in ionic salts. Elemental potassium is a soft silvery-white alkali metal that oxidizes rapidly in air and reacts vigorously with water, generating sufficient heat to ignite hydrogen emitted in the reaction and burning with a lilac- colored flame. It is found dissolved in sea water (which is 0.04% potassium by weight), and is part of many minerals.
Potassium is chemically very similar to sodium, the previous element in Group 1 of the periodic table. They have a similar ionization energy, which allows for each atom to give up its sole outer electron. That they are different elements that combine with the same anions to make similar salts was suspected in 1702, and was proven in 1807 using electrolysis.
Most industrial applications of potassium exploit the high solubility in water of potassium compounds, such as potassium soaps. Heavy crop production rapidly depletes the soil of potassium, and this depletion is prevented and remedied with agricultural fertilizers containing potassium, accounting for 95% of global potassium chemical production.
Potassium ions are necessary for the function of all living cells. The transfer of potassium ions through nerve cell membranes is necessary for normal nerve transmission; potassium depletion in excess can result in numerous abnormalities, including an abnormal heart rhythm and various electrocardiographic (ECG) abnormalities. Fresh fruits and vegetables are good dietary sources of potassium. The body responds to the influx of dietary potassium, which raises serum potassium levels, with a shift of potassium from outside to inside cells and an increase in potassium excretion by the kidney.
Usage examples of "potassium".
Add 20 grams of sodium acetate, warm, and precipitate the lead with a dilute solution of potassium chromate.
The addition of potassium chromate to the acetate solution reprecipitates the lead as a yellow chromate.
From baryta, which it also resembles, it is distinguished by not yielding an insoluble chromate in an acetic acid solution, by the solubility of its chloride in alcohol, and by the fact that its sulphate is converted into carbonate on boiling with a solution formed of 3 parts of potassium carbonate and 1 of potassium sulphate.
It is also suggested that the fingerprint examiner wear rubber gloves when using acetone, benzine, xylene, formaldehyde, potassium hydroxide, or sodium hydroxide.
Nessler tube and the colour compared with that observed in a similar tube containing water and potassium iodide on adding the standard solution of bismuth.
The less pure samples will show an excess of alkalinity because of the presence of sodium carbonate or of potassium carbonate.
In systematic assays of this kind, the alkalinity would no doubt be generally in excess of that required by the cyanide present: there would be no inconvenience in recording such excess in terms of potassium cyanide.
Seys and Brewer, 1858, applied aqueous solutions of ferrocyanide of potassium or other salts, which formed an indelible compound with the ferruginous base of writing ink.
The various explosives, such as gunpowder, black blasting powder, potassium chlorate powders, nitro-glycerine powders, etc.
I shook and brushed myself dry, took a couple of food tablets, and put a new potassium chlorate cube in the electrolyser of the mask.
Dissolve in gasoline and pour this liquid onto 90 parts potassium chlorate crystals in a plastic bowl.
For example, when a spy writes in iron sulfate, nothing will be visible until it is painted over with a solution of potassium cyanate, when the two chemicals will combine to form ferric ferrocyanide, or Prussian blue, a particularly lovely hue.
This property is made use of in determining the quantity of uranium in pure solutions by titrating with permanganate of potassium solution as in the case with iron.
The quantity of iron peroxidised is determined by taking a known quantity of ferrous salt, oxidizing with a weighed sample of nitrate, and then determining the residual ferrous iron by titration with bichromate or permanganate of potassium solution.
Soluble ferrocyanides, ferricyanides, and sulphocyanides of various metals, by forming dibasic salts with potassium, sodium, or ammonium, in conjunction with vegetable, animal, or metallic coloring matters.