Period 5 element and because of its rarity, rhodium is usually alloyed with platinum or palladium and applied in high-temperature and corrosion-resistive coatings. White gold is often plated with a thin rhodium layer to improve its optical impression while sterling silver is often rhodium plated for tarnish resistance. Rhodium detectors are used in nuclear reactors to measure the neutron flux level. Palladium is a chemical element with the chemical symbol Pd and an atomic number of 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
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.