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Properties of Matter Element Card 16, Lesson 21



Melting point

63° C

Boiling point

7607° C


.86 g/cm³


Potassium is usually covered with a layer of dull gray oxide. However, when it is scratched, a shiny silver color is revealed.

Other physical properties

Potassium is soft enough to be cut easily with a knife. It is not magnetic, but it is a good conductor of heat and electricity.

Chemical properties

Potassium is very reactive. It even catches fire when put in water.


Potassium forms white crystalline compounds




Potassium is extracted from potassium chloride by electrolysis. It is the seventh most abundant element in Earth's crust.

potassium reacting in water Potassium reacting in water

When potassium is dropped in water, it reacts violently, producing hydrogen gas, which is ignited by the heat produced during the reaction.


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