The Scottish chemist William Ramsay discovered helium, argon, xenon, krypton and neon in the space of a few years, adding a new group to the periodic table
Source:
https://www.newscientist.com/article/2218441-sir-william-ramsay-added-a-whole-new-group-to-the-periodic-table/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home