Praseodymium Arsenide

See more Arsenic products. Arsenic (atomic symbol: As, atomic number: 33) is a Block P, Group 15, Period 4 element with an atomic radius of 74.92160. The number of electrons in each of arsenic's shells is 2, 8, 18, 5 and its electron configuration is [Ar] 3d¹⁰ 4s² 4p³. The arsenic atom has a radius of 119 pm and a Van der Waals radius of 185 pm. Arsenic was discovered in the early Bronze Age, circa 2500 BC. It was first isolated by Albertus Magnus in 1250 AD. In its elemental form, arsenic is a metallic grey, brittle, crystalline, semimetallic solid. Arsenic is found in numerous minerals including arsenolite (As₂O₃), arsenopyrite (FeAsS), loellingite (FeAs₂), orpiment (As₂S₃), and realgar (As₄S₄). Arsenic has numerous applications as a semiconductor and other electronic applications as indium arsenide, silicon arsenide and tin arsenide. Arsenic is finding increasing uses as a doping agent in solid-state devices such as transistors.

See more Praseodymium products. Praseodymium (atomic symbol: Pr, atomic number: 59) is a Block F, Group 3, Period 6 element with an atomic weight of 140.90765. The number of electrons in each of praseodymium's shells is 2, 8, 18, 21, 8, 2 and its electron configuration is [Xe]4f³ 6s². The praseodymium atom has a radius of 182 pm and a Van der Waals radius of 239 pm. Praseodymium resembles the typical trivalent rare earths, however, it will exhibit a +4 state when stabilized in a zirconia host. Unlike other rare-earth metals, which show antiferromagnetic and / or ferromagnetic ordering at low temperatures, praseodymium is paramagnetic at any temperature above 1 K. Praseodymium is found in the minerals monazite and bastnasite. Praseodymium was discovered by Carl Auer von Welsbach in 1885. The origin of the element name comes from the Greek words prasios didymos, meaning green twin.