Name Potassium
Symbol K
Atomic Number 19
Atomic Mass 39.0983 atomic mass units
Number of Protons 19
Number of Neutrons 20
Number of Electrons 19
Melting Point 63.65 C
Boiling Point 774.0 C
Density .862 grams per cubic centimeter
Normal Phase Solid
Family Alkali Metals
Period 4



Origin of Name From the English word potash, meaning pot ashes, and the Arabic word qali, meaning alkali. The symbol K comes from the Latin word kalium, meaning alkali.
Date and Place of Discovery In 1807 in London, England
Discovered by Sir Humphry Davy
Common Compounds
Interesting facts
  • It was the first metal to be isolated using electrolysis.
  • It catches fire when exposed to water.
  • It burns with a violet flame.
  • It is found in all living plant and animal cells.
  • The human body uses it to promote regular heartbeat, help build muscles, help contract muscles, regulate blood pressure, and control the water balance in body tissues and cells.
  • A diet low in potassium and high in sodium can lead to high blood pressure.
Common Uses
  • Soaps
  • Glassware
  • Matches
  • Explosives
  • Heat-transfer systems
  • Helps human metabolism
  • Medications


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