Antimony Chromium

See more Antimony products. Antimony (atomic symbol: Sb, atomic number: 51) is a Block P, Group 15, Period 5 element with an atomic radius of 121.760. The number of electrons in each of antimony's shells is 2, 8, 18, 18, 5 and its electron configuration is [Kr] 4d¹⁰ 5s² 5p³. The antimony atom has a radius of 140 pm and a Van der Waals radius of 206 pm. Antimony was discovered around 3000 BC and first isolated by Vannoccio Biringuccio in 1540 AD. In its elemental form, antimony has a silvery lustrous gray appearance. The most common source of antimony is the sulfide mineral known as stibnite (Sb₂S₃), although it sometimes occurs natively as well. Antimony has numerous applications, most commonly in flame-retardant materials. It also increases the hardness and strength of lead when combined in an alloy and is frequently employed as a dopant in semiconductor materials. Its name is derived from the Greek words anti and monos, meaning a metal not found by itself.

See more Chromium products. Chromium (atomic symbol: Cr, atomic number: 24) is a Block D, Group 6, Period 4 element with an atomic weight of 51.9961. The number of electrons in each of Chromium's shells is 2, 8, 13, 1 and its electron configuration is [Ar] 3d⁵ 4s¹. Louis Nicolas Vauquelin first discovered chromium in 1797 and first isolated it the following year. The chromium atom has a radius of 128 pm and a Van der Waals radius of 189 pm. In its elemental form, chromium has a lustrous steel-gray appearance. Chromium is the hardest metallic element in the periodic table and the only element that exhibits antiferromagnetic ordering at room temperature, above which it transforms into a paramagnetic solid. The most common source of chromium is chromite ore (FeCr₂O₄). Due to its various colorful compounds, Chromium was named after the Greek word 'chroma.' meaning color.