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
Earth (classical element) by a horizontal line. Prithvi (Sanskrit: ', also ') is the Hindu "earth" and mother goddess. According to one such tradition, she is the personification of the Earth itself; according to another, its actual mother, being "Prithvi Tattwa", the essence of the element earth. As "Prithvi Mata", or "Mother Earth", she contrasts with "Dyaus Pita", "father sky". In the Rigveda, "earth" and sky are frequently addressed as a duality, often indicated by the idea of two complementary "half-shells." In addition, the element Earth is associated with Budha or Mercury who represents communication, business, mathematics and other practical matters. Earth and