kalíum
Kalíum, also spelled kalium, is a chemical element with the symbol K and atomic number 19. It is a soft, silvery‑white alkali metal in group 1 of the periodic table. Kalíum is highly reactive, tarnishes in air, and must be stored under oil or in an inert atmosphere. It has a low density and a low melting point of about 63.5°C. In chemistry it most commonly adopts the +1 oxidation state and forms a wide range of compounds, such as potassium chloride (KCl), potassium hydroxide (KOH), and potassium carbonate (K2CO3).
Natural occurrence and production. Kalíum is abundant in the Earth’s crust and occurs mainly in minerals and
Isotopes and biology. Naturally occurring kalíum consists predominantly of the stable isotopes 39K and 41K, with
Safety and uses. As a reactive metal, kalíum is handled with care to avoid contact with moisture.