6th October: Discovery of Potassium

Potassium was first discovered on this date in 1807 by Sir Humphrey Davy. 10 things you might not know about potassium:

1. It is a very light and soft metal. It is so soft that in its pure form, it can be cut with a knife. Freshly cut potassium is silvery in appearance, but it begins to tarnish toward grey immediately after being exposed to air.
2. Potassium compounds emit a lilac or violet flame when burned.
3. Potassium is the second least dense metal after lithium.
4. Potassium was the first metal to be isolated using electrolysis.
5. In its various compounds, potassium makes up about 2.6% of the weight of the Earth's crust and is the seventh most abundant element. Granite contains 5% potassium, well above the average in the Earth's crust.
6. In nature, it is only found in compounds, because it reacts violently with many other things, most notably oxygen and water. It was originally created inside type II supernovas.
7. The name potassium was derived from potash, from which the element was first isolated. It has the unlikely seeming chemical symbol K from a Neo-Latin word, Kalium, meaning alkali, which in turn came from an Arabic word meaning "plant ashes".
8. Potassium is a vital element for all living cells, including ours. It helps with nerve transmissions. Foods rich in potassium include yam, Parsley, dried Apricots, dried Milk, Chocolate, various nuts (especially Almonds and Pistachios), Potatoes, Bamboo shoots, Bananas, Avocados, soybeans, and bran, although it is also present in sufficient quantities in most fruits, vegetables, meat and fish.
9. Potassium carbonate (K2CO3 or potash) is used in the manufacture of glass, soap, colour TV tubes, fluorescent lamps, textile dyes and pigments. In 1840, Justus Liebig discovered that potassium is a necessary element for plants and that most types of soil lack potassium. His discovery caused a steep rise in demand for potassium based fertilizers.
10. The superoxide KO2 is an orange solid that acts as a portable source of Oxygen and a carbon dioxide absorber. It is widely used in respiration systems in mines, submarines and spacecraft because it takes up less volume than gaseous oxygen.