Potassium
🍌 In Your World
Potassium is an essential mineral for all life. You get it from many foods, most famously bananas, as well as potatoes and spinach. In your body, it's a vital electrolyte that helps regulate fluid balance, muscle contractions, and nerve signals. Its most significant commercial use is in fertilizers (as potash), which are crucial for growing crops.
📖 The Discovery Story
Like other alkali metals, potassium is too reactive to be found free in nature. It was first isolated in 1807 by English chemist Sir Humphry Davy, just a few days after he isolated sodium. He used electrolysis on molten caustic potash (KOH). The name "potassium" comes from "potash," while its symbol, K, is derived from kalium, the Medieval Latin name for potash.
📊 Properties at a Glance
| Phase at STP | Solid |
| Melting Point | 63.5 °C / 146.3 °F |
| Boiling Point | 759 °C / 1398 °F |
| Electron Configuration | [Ar] 4s¹ |
| Abundance in Earth's Crust | 2.09% |
⚠️ Safety & Handling
Potassium metal is even more reactive than sodium. It reacts violently with water, producing flammable hydrogen gas that often ignites from the heat of the reaction, causing a lilac-colored flame. It must be stored under an inert medium like mineral oil to prevent it from reacting with air.