Mechanochemical Decomposition of Crystalline Cellulose in the Presence of Protonated Layered Niobium Molybdate Solid Acid Catalyst.

See more Niobium products. Niobium (atomic symbol: Nb, atomic number: 41) is a Block D, Group 5, Period 5 element with an atomic weight of 92.90638. The number of electrons in each of niobium's shells is 2, 8, 18, 12, 1 and its electron configuration is [Kr] 4d⁴ 5s¹. The niobium atom has a radius of 146 pm and a Van der Waals radius of 207 pm. Niobium was discovered by Charles Hatchett in 1801 and first isolated by Christian Wilhelm Blomstrand in 1864. In its elemental form, niobium has a gray metallic appearance. Niobium has the largest magnetic penetration depth of any element and is one of three elemental type-II superconductors (along with vanadium and technetium). Niobium is found in the minerals pyrochlore, its main commercial source, and columbite. The word Niobium originates from Niobe, daughter of mythical Greek king Tantalus.

See more Molybdenum products. Molybdenum (atomic symbol: Mo, atomic number: 42) is a Block D, Group 6, Period 5 element with an atomic weight of 95.96. The number of electrons in each of molybdenum's shells is [2, 8, 18, 13, 1] and its electron configuration is [Kr] 4d⁵ 5s¹. The molybdenum atom has a radius of 139 pm and a Van der Waals radius of 209 pm. In its elemental form, molybdenum has a gray metallic appearance. Molybdenum was discovered by Carl Wilhelm in 1778 and first isolated by Peter Jacob Hjelm in 1781. Molybdenum is the 54th most abundant element in the earth's crust. It has the third highest melting point of any element, exceeded only by tungsten and tantalum. Molybdenum does not occur naturally as a free metal, it is found in various oxidation states in minerals. The primary commercial source of molybdenum is molybdenite, although it is also recovered as a byproduct of copper and tungsten mining. The origin of the name Molybdenum comes from the Greek word molubdos meaning lead.