Wikijunior:The Elements/Potassium

Shows the position of Potassium on the periodic chart.
Potassium's symbol on the Periodic Table

What does it look, feel, taste, or smell like?

Potassium feldspar

Potassium is metallic and silvery white. It is soft, waxy and can easily be cut with a knife. Potassium has a lilac colored flame and burns when in contact with water. It reacts with oxygen to form potassium superoxide ( ) and with water to form potassium hydroxide ( ), hydrogen gas and heat. Enough heat is produced to ignite the hydrogen gas.

How was it discovered?


It was discovered in 1807 when Sir Humphrey Davy extracted it from potassium hydroxide (or caustic potash, KOH,) a compound used in cooking.

Where did its name come from?


The name "potassium" comes from the Dutch word Potasch. Potassium was discovered in 1807 in England by Sir Humphry Davy.

Potassium's chemical symbol, K, comes from the Arabic word القلية (al-qalya), meaning potash, formed into the Latin word "kalium", most likely because it is an alkali metal.

Did You Know?

Potassium is important for your nerves and muscles.

Where is it found?


Potassium makes up nearly 3% of the Earth's crust and is the seventh most abundant element on the planet. Potassium is rarely found free in nature as it is a very reactive element. Instead, potassium is usually found in minerals such as sylvite, carnallite, langbeinite, and polyhalite. These minerals are usually found in ancient lake and sea beds. Another important source of potassium, caustic potash, is mined in Germany as well as New Mexico, California and Utah in the United States.

What are its uses?


Plants need potassium to grow. Potassium can be found it most soils, usually in the form of potassium chloride (KCl) or potassium nitrate (KNO3). In addition, potassium chloride is a salt substitute and aids in the production of other chemicals. Potassium nitrate, also known as saltpeter or niter, is also used to make the heads of matches and pyrotechnics (it is the major component of gunpowder.) Potassium hydroxide (KOH) can be found in soaps, detergents and drain cleaners. Potassium carbonate (KHCO3), or pearl ash, is a byproduct of ammonia that can be found in certain types of soap and glass. Potassium is also found in bananas.

Is it dangerous?


Pure potassium, as a metal, will light on fire if it touches water. However, potassium is a required mineral in the body as an ion — an electric atom. One of its uses inside the body is in the nerves. Nerves, and neurons in the brain, carry electricity; the potassium ion, along with the sodium ion, are important to this.

Potassium hydroxide and its solutions should never be touched in any way, as they are EXTREMELY POISONOUS AND CORROSIVE!!!!!!!!!!!!!!!!!!!.