Palladium Palladium Palladium is a chemical element with symbol Pd and atomic number 46. It is a rare and lustrous silvery-white metal discovered in 1803 by William Hyde Wollaston. He named it after the asteroid Pallas, which was itself named after the epithet of the Greek goddess Athena, acquired by her when she slew Pallas. Palladium, platinum, rhodium, ruthenium, iridium and osmium form a group of elements referred to as the platinum group metals (PGMs). These have similar chemical properties, but palladium has the lowest melting point and is the least dense of them. More than half the supply of palladium
Root element Root element Each XML document has exactly one single root element. It encloses all the other elements and is therefore the sole parent element to all the other elements. ROOT elements are also called document elements. In HTML, the root element is the codice_1 element. The World Wide Web Consortium defines not only the specifications for XML itself, but also the DOM, which is a platform- and language-independent standard object model for representing XML documents. DOM Level 1 defines, for every XML document, an object representation of the codice_2 itself and an attribute or property on the document called codice_3.