Quantum size confinement in gallium selenide nanosheets: band gap tunability versus stability limitation.

See more Gallium products. Gallium (atomic symbol: Ga, atomic number: 31) is a Block P, Group 13, Period 4 element with an atomic weight of 69.723.The number of electrons in each of Gallium's shells is 2, 8, 18, 3 and its electron configuration is [Ar] 3d¹⁰ 4s² 4p¹. The gallium atom has a radius of 122.1 pm and a Van der Waals radius of 187 pm. Gallium was predicted by Dmitri Mendeleev in 1871. It was first discovered and isolated by Lecoq de Boisbaudran in 1875. In its elemental form, gallium has a silvery appearance. Gallium is one of three elements that occur naturally as a liquid at room temperature, the other two being mercury and cesium. Gallium does not exist as a free element in nature and is sourced commercially from bauxite and sphalerite. Currently, gallium is used in semiconductor devices for microelectronics and optics. The element name originates from the Latin word 'Gallia' referring to Gaul, the old name of France.

See more Selenium products. Selenium (atomic symbol: Se, atomic number: 34) is a Block P, Group 16, Period 4 element with an atomic radius of 78.96. The number of electrons in each of Selenium's shells is 2, 8, 18, 6 and its electron configuration is [Ar] 3d¹⁰ 4s² 4p⁴. The selenium atom has a radius of 120 pm and a Van der Waals radius of 190 pm. Selenium is a non-metal with several allotropes: a black, vitreous form with an irregular crystal structure three red-colored forms with monoclinic crystal structures and a gray form with a hexagonal crystal structure, the most stable and dense form of the element. One of the most common uses for selenium is in glass production the red tint that it lends to glass neutralizes green or yellow tints from impurities in the glass materials. Selenium was discovered and first isolated by Jöns Jakob Berzelius and Johann Gottlieb Gahn in 1817. The origin of the name Selenium comes from the Greek word "Selênê," meaning moon.