POTASSIUM


Symbol: K
Group #: 1
Group Name: Alkali Metals
Atomic #: 19
Mass #: 39
Atomic Mass: 39.0983

Electron Configuration: 1s22s22p63s23p64s1
Boiling Point: 76.6°C
Melting Point: 63.2°C
Density: .856g/ml
Radioactivity: 40K
Color: Silverish
Odor: None
Hardness: Low
Brittle: Low
Malleability: High
 
Chemical Properties: (Click here for Demonstrations!! )
Potassium is a very reactive metal.  It is very reactive with both water and oxygen.  Because of this, potassium should be stored in a liquid such as kerosene or mineral oil.  Potassium is not a manmade element, however some isotopes have been artificially prepared.  It occurs naturally combined with other minerals such as sylite or carnallite.  Potassium makes up about 2.5% of the earth's crust, and plays an important role in our bodies.
 
History:
Potassium was discovered in 1807 by Sir Humphry Davy.  Davy also discovered sodium, barium, strontium, calcium, and magnesium.  Davy used a process called electrolysis to isolate the potassium.  Electrolysis is a process in which an electric curent is passed through an electrolyte until the substance splits into the elements or compounds that make it up.
 
Uses:
There are many uses for potassium today.  Potassium bromide is used in medicine as a seditive, and in photography, lithography, and engraving.  Potassium chromate and bichromate are powerful oxidizing agents and are found in fireworks.  Potassium iodide is used in medicine to treat rheumatism and some thyroid conditions.  Potassium nitrate is used in explosives, fireworks, and matches.  Potassium permanganate is used as a disinfectant and a germacide.  Potassium sulfate is used in fertilizer.  Finally, potassium hydrogen tartrate, also known as cream of tartar is used in baking.  Potassium is required in our bodies for metabolism and the sending of messages in our brain, called neuron firing.
 
References:
MarkWinter. (1999) Potassium, [online]. Avaliable: http://www.webelements.com/webelements/elements/text/key/K.html(pg.1-4)
 
Unknown. (1999). Potassium, [online]. Avaliable:
http://www.chemsoc.com/viselements/pages/pdf/potassium.PDF(pg.1-2)
 
Unknown. (1999). Potassium, [online]. Avaliable: http://www.funkandwagnalls.com/encyclopedia/low/articles/p/p020000632f.html(pg.1-2)
 
Unknown. (1999). Potassium, [online]. Avaliable: http://www.bvsd.k12.co.us/schools/BHS/science/elements/potassiu.html(pg.1-1)
 
Unknown. (1999). Humphry Davy, [online]. Avaliable: http://www.spatacus.schoolnet.co.Uk./SCdavy.htm(pg.1-3)

Matt F.                                        Past Element Projects: Fall 1999
June 6, 2000