Effect of Gypsum on the Early Hydration of Cubic and Na-Doped Orthorhombic Tricalcium Aluminate.

See more Aluminum products. Aluminum (or Aluminium) (atomic symbol: Al, atomic number: 13) is a Block P, Group 13, Period 3 element with an atomic weight of 26.9815386. It is the third most abundant element in the earth's crust and the most abundant metallic element. Aluminum's name is derived from alumina, the mineral from which Sir Humphrey Davy attempted to refine it from in 1812. Aluminum was first predicted by Antoine Lavoisier 1787 and first isolated by Hans Christian Øersted in 1825. Aluminum is a silvery gray metal that possesses many desirable characteristics. It is light, nonmagnetic and non-sparking. It stands second among metals in the scale of malleability, and sixth in ductility. It is extensively used in many industrial applications where a strong, light, easily constructed material is needed. Although it has only 60% of the electrical conductivity of copper, it is used in electrical transmission lines because of its light weight. Pure aluminum is soft and lacks strength, but alloyed with small amounts of copper, magnesium, silicon, manganese, or other elements, it imparts a variety of useful properties.

See more Calcium products. Calcium (atomic symbol: Ca, atomic number: 20) is a Block S, Group 2, Period 4 element with an atomic weight of 40.078. The number of electrons in each of Calcium's shells is [2, 8, 8, 2] and its electron configuration is [Ar]4s². The calcium atom has a radius of 197 pm and a Van der Waals radius of 231 pm. Calcium was discovered and first isolated by Sir Humphrey Davy in 1808. It is the fifth most abundant element in the earth's crust and can be found in minerals such as dolomite, gypsum, plagioclases, amphiboles, pyroxenes and garnets. In its elemental form, calcium has a dull gray-silver appearance. Calcium is a reactive, soft metal that is a member of the alkaline earth elements. It frequently serves as an alloying agent for other metals like aluminum and beryllium, and industrial materials like cement and mortar are composed of calcium compounds like calcium carbonate. It is also an biologically essential substance found in teeth, bones, and shells. The name "calcium" originates from the Latin word "calics," meaning lime.