Evaluation of ultrasound assisted potassium permanganate pre-treatment of spent coffee waste.

See more Potassium products. Potassium (atomic symbol: K, atomic number: 19) is a Block S, Group 1, Period 4 element with an atomic weight of 39.0983. The number of electrons in each of Potassium's shells is [2, 8, 8, 1] and its electron configuration is [Ar] 4s¹. The potassium atom has a radius of 227.2 pm and a Van der Waals radius of 275 pm. Potassium was discovered and first isolated by Sir Humphrey Davy in 1807. Potassium is the seventh most abundant element on earth. It is one of the most reactive and electropositive of all metals and rapidly oxidizes. As with other alkali metals, potassium decomposes in water with the evolution of hydrogen because of its reacts violently with water, it only occurs in nature in ionic salts. In its elemental form, potassium has a silvery gray metallic appearance, but its compounds (such as potassium hydroxide) are more frequently used in industrial and chemical applications. The origin of the element's name comes from the English word 'potash,' meaning pot ashes, and the Arabic word qali, which means alkali. The symbol K originates from the Latin word kalium.

See more Manganese products. Manganese (atomic symbol: Mn, atomic number: 25) is a Block D, Group 7, Period 4 element with an atomic weight of 54.938045. The number of electrons in each of Manganese's shells is [2, 8, 13, 2] and its electron configuration is [Ar] 3d⁵ 4s². The manganese atom has a radius of 127 pm and a Van der Waals radius of 197 pm. Manganese was first discovered by Torbern Olof Bergman in 1770 and first isolated by Johann Gottlieb Gahn in 1774. In its elemental form, manganese has a silvery metallic appearance. It is a paramagnetic metal that oxidizes easily in addition to being very hard and brittle. Manganese is found as a free element in nature and also in the minerals pyrolusite, braunite, psilomelane, and rhodochrosite. The name Manganese originates from the Latin word mangnes, meaning "magnet."