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
Element (UML) Element (UML) In the Unified Modeling Language (UML), an Element is an abstract class with no superclass. It is used as the superclass or base class, as known by object oriented programmers, for all the metaclasses in the UML infrastructure library. All other elements in the UML inherit, directly or indirectly from Element. An Element has a derived composition association to itself to support the general capability for elements to own other elements. As such, it has no additional attributes as part of its specification. An association describes a set of tuples of typed instances. The Element class belongs to