Discovery Information
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Who: Sir Humphrey Davy |
When: 1807 |
Where: England |
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Name Origin
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From potash (pot ash); K from latin: kalium |
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Sources
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Found in minerals like carnallite and sylvite (KCl). Potassium makes up about 2.40% of the weight of the Earth's crust, it
is the seventh most abundant element. The main sources of potash are mined in USA (California, New Mexico and Utah) and Germany.,
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Uses
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Used as potash (potassium carbonate) in making glass, soap, lenses and salt substitute. Also as potassium nitrate (KNO3, also called saltpeter) it is used to make explosives and to colour fireworks in mauve.
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Glass treated with liquid potassium is much stronger than regular glass. |
Potassium chloride (KCl) is used as a substitute for table salt and is also used to stop the heart, e.g. in cardiac surgery
and in executions by lethal injection in solution.
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Notes
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Solid potassium reacts violently with water, and should therefore be kept under a mineral oil such as kerosene and handled
with care. When in water, it may catch fire spontaneously, burning with a purple flame. Unlike lithium and sodium however, potassium cannot be stored under oil indefinitely. If stored longer than 6 months to a year, dangerous shock-sensitive
peroxides can form on the metal and under the lid of the container that can detonate upon opening.
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Potassium is a necessary mineral in daily nutrition; it assists in muscle contraction and in maintaining fluid and electrolyte
balance in body cells.
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Formerly called kalium hence the symbol 'K'. |