109 years ago today, on July 23, 1916 (June 24, 1916 in the lunar calendar), British chemist Sir William Ramsey passed away. Sir William Ramsay, KCB(October 2, 1852-July 23, 1916) was a British chemist and winner of the 1904 Nobel Prize in Chemistry. From 1887, William Ramsey went to University College London to serve as chairman of the Department of Chemistry. The most famous research results of his life came from this period. Between 1885 and 1890, he published several important papers on nitrogen oxides. These studies laid the foundation for his later more outstanding results. On the evening of April 19, 1894, Ramsey attended a lecture given by Riley. Rayleigh previously discovered that nitrogen obtained by ammonium nitrite decomposition has different densities from "nitrogen" extracted from air. After discussion with Ramsey, Rayleigh decided to jointly explore the reasons for this phenomenon. They immediately started research on this in their respective laboratories and kept in contact almost every day to inform each other of the progress of their work. In August of the same year, Ramsey and Rayleigh announced the discovery of argon. In 1895, he isolated helium from ytterite, proving that this element, previously only observed by the French astronomer Pierre Janssen in the solar spectrum, also existed on Earth. In the following years, Ramsey discovered neon, krypton and xenon one after another. In 1903, he collaborated with Frederic Sodi to detect helium in radium emissions. In 1910, he and Robert Whitelow-Gray isolated radon and determined its density to be the highest of any known gas. In 1904, William Ramsay was awarded the Nobel Prize in Chemistry for "discovering noble gas elements in the air and determining their positions in the periodic table of elements." Comment: He discovered several inert elements.