Effect of pre-treatment of bentonite with sodium and calcium ions on phosphate adsorption onto zirconium-modified bentonite.

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.

See more Sodium products. Sodium (atomic symbol: Na, atomic number: 11) is a Block D, Group 5, Period 4 element with an atomic weight of 22.989769. The number of electrons in each of Sodium's shells is [2, 8, 1] and its electron configuration is [Ne] 3s¹. The sodium atom has a radius of 185.8 pm and a Van der Waals radius of 227 pm. Sodium was discovered and first isolated by Sir Humphrey Davy in 1807. In its elemental form, sodium has a silvery-white metallic appearance. It is the sixth most abundant element, making up 2.6 % of the earth's crust. Sodium does not occur in nature as a free element and must be extracted from its compounds (e.g., feldspars, sodalite, and rock salt). The name Sodium is thought to come from the Arabic word suda, meaning "headache" (due to sodium carbonate's headache-alleviating properties), and its elemental symbol Na comes from natrium, its Latin name.

See more Zirconium products. Zirconium (atomic symbol: Zr, atomic number: 40) is a Block D, Group 4, Period 5 element with an atomic weight of 91.224. The number of electrons in each of Zirconium's shells is 2, 8, 18, 10, 2 and its electron configuration is [Kr]4d² 5s². The zirconium atom has a radius of 160 pm and a Van der Waals radius of 186 pm. Zirconium was discovered by Martin Heinrich Klaproth in 1789 and first isolated by Jöns Jakob Berzelius in 1824. In its elemental form, zirconium has a silvery white appearance that is similar to titanium. Zirconium's principal mineral is zircon (zirconium silicate). Zirconium is commercially produced as a byproduct of titanium and tin mining and has many applications as a opacifier and a refractory material. It is not found in nature as a free element. The name of zirconium comes from the mineral zircon, the most important source of zirconium, and from the Persian wordzargun, meaning gold-like.

See more Phosphorus products. Phosphorus (atomic symbol: P, atomic number: 15) is a Block P, Group 15, Period 3 element. The number of electrons in each of Phosphorus's shells is 2, 8, 5 and its electronic configuration is [Ne] 3s² 3p³. The phosphorus atom has a radius of 110.5.pm and its Van der Waals radius is 180.pm. Phosphorus is a highly-reactive non-metallic element (sometimes considered a metalloid) with two primary allotropes, white phosphorus and red phosphorus its black flaky appearance is similar to graphitic carbon. Compound forms of phosphorus include phosphates and phosphides. Phosphorous was first recognized as an element by Hennig Brand in 1669 its name (phosphorus mirabilis, or "bearer of light") was inspired from the brilliant glow emitted by its distillation.