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
Chalcogen was associated with metals and metal-bearing rock in general; copper, and its alloy bronze, was one of the first metals to be used by humans. Oxygen's name comes from the Greek words "oxy genes", meaning "acid-forming". Sulfur's name comes from either the Latin word "sulfurium" or the Sanskrit word "sulvere"; both of those terms are ancient words for sulfur. Selenium is named after the Greek goddess of the moon, Selene, to match the previously-discovered element tellurium, whose name comes from the Latin word "telus", meaning earth. Polonium is named after Marie Curie's country of birth, Poland. Livermorium is named for