Lanthanum 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 Lanthanum products. Lanthanum (atomic symbol: La, atomic number: 57) is a Block F, Group 3, Period 6 element with an atomic weight of 138.90547. The number of electrons in each of lanthanum's shells is [2, 8, 18, 18, 9, 2] and its electron configuration is [Xe] 5d¹ 6s². The lanthanum atom has a radius of 187 pm and a Van der Waals radius of 240 pm. Lanthanum was first discovered by Carl Mosander in 1838. In its elemental form, lanthanum has a silvery white appearance. It is a soft, malleable, and ductile metal that oxidizes easily in air. Lanthanum is the first element in the rare earth or lanthanide series. It is the model for all the other trivalent rare earths and it is the second most abundant of the rare earths after cerium. Lanthanum is found in minerals such as monazite and bastnasite. The name lanthanum originates from the Greek word Lanthaneia, which means 'to lie hidden'.