Potassium

3 definitions found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  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).


     [1913 Webster]
  
     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.
           [1913 Webster]
  
     {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}.
        [1913 Webster]

From WordNet (r) 2.0 [wn]:

  potassium
       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}]

From Elements database 20001107 [elements]:

  potassium
  Symbol: K
  Atomic number: 19
  Atomic weight: 39.0983
  Soft silvery metallic element belonging to group 1 of the periodic table
  (alkali metals). Occurs naturally in seawater and a many minerals. Highly
  reactive, chemically, it resembles sodium in its behavior and compounds.
  Discovered by Sir Humphry Davy in 1807.