Kr Krypton 36 83.798 18 4 p 36 -157.0 -152.0 [Ar] 3d10 4s2 4p6 2 8 18 8 0.00374 1.5E-8% Colorless Cubic: Face centered 3.0 2.966 {"1":"1350.8","2":"2350.4","3":"3565","4":"5070","5":"6240","6":"7570","7":"10710","8":"12138","9":"22274","10":"25880","11":"29700","12":"33800","13":"37700","14":"43100","15":"47500","16":"52200","17":"57100","18":"61800","19":"75800","20":"80400","21":"85300","22":"90400","23":"96300","24":"101400","25":"111100","26":"116290","27":"282500","28":"296200","29":"311400","30":"326200"} 1356 0 110 0 1.03 32.2 1.638 9.029 0.248 0.00949 0 Gas, Diamagnetic, NobleGas, Nonmetal, Stable, Natural KRIP-ton Colorless, odorless, tasteless rare noble gas. Used in lighting products. Some is used as inert filler-gas in incandescent bulbs. Some is mixed with argon in fluorescent lamps. The most important use is in flashing stroboscopic lamps that outline airport runways. Forms 1 millionth of the atmosphere. Obtained from production of liquid air. il4OOY7Zseg Krypton

By the mid-18th century, Swedish chemist Carl Wilhelm Scheele had used pyrolusite to produce chlorine.

Scheele and others were aware that pyrolusite contained a new element, but they were not able to isolate it.

Johan Gottlieb Gahn was the first to isolate an impure sample of manganese metal in 1774, by reducing the dioxide with carbon. From the Latin word magnes, magnet, from magnetic properties of pyrolusite 36 1898 Sir William Ramsay, Morris W. Travers Great Britain From the Greek word "kryptos" meaning "hidden"

Excess manganese, particularly inhalation of the powder, is toxic

Neanderthals may have used black manganese di oxide as a cosmetic 50,000 years ago

For over 2000 years, manganese dioxide has been used to make colorless glass.

Manganese dioxide is used as the cathode material in zinc-carbon and alkaline batteries.

Manganese also functions in the oxygen-evolving complex of photosynthetic plants.

The dioxide is also used in the preparation of oxygen and chlorine and in drying black paints.