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
Effective atomic number possible to obtain a much more accurate single-valued Z by weighting against the spectrum of the source. The effective atomic number for electron interactions may be calculated with a similar approach; see for instance Taylor "et al." 2009 and Taylor 2011. The cross-section based approach for determining Z is obviously much more complicated than the simple power-law approach described above, and this is why freely-available software has been developed for such calculations (Taylor "et al." 2012). Effective atomic number Effective atomic number has two different meanings: one that is the effective nuclear charge of an atom, and one that calculates