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
307 Nike 307 Nike Nike (minor planet designation: 307 Nike) is a sizeable asteroid of the asteroid belt. It was discovered by Auguste Charlois on 5 March 1891 while working at the Nice Observatory. Charlois named it after the Greek goddess of victory, as well as the Greek name for the city where it was discovered. Measurement of the light curve of this asteroid in 2000 indicates a rotation period of 7.902 ± 0.005 hours. On December 2, 1972, Pioneer 10 made one of its nearest passages of an asteroid when it passed 307 Nike at a distance of about 8.8 million