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
Mercury (element) of 46.612 days. Most of the remaining radioisotopes have half-lives that are less than a day. and are the most often studied NMR-active nuclei, having spins of and respectively. Hg is the modern chemical symbol for mercury. It comes from "hydrargyrum", a Latinized form of the Greek word ὑδράργυρος ("hydrargyros"), which is a compound word meaning "water-silver" (from ὑδρ- "hydr-", the root of ὕδωρ, "water," and ἄργυρος "argyros" "silver") – since it is liquid like water and shiny like silver. The element was named after the Roman god Mercury, known for his speed and mobility. It is associated with the