Geology Study reveals 'flawed argument' in debate over when plate tectonics began. ... This German periodic table classroom poster, dating to 1885, may be the oldest surviving in the world.

With the discovery, the girl with the Jemison poster on her wall had “claimed a seat at the periodic table,” Phelps said in her TEDx Talk. But despite the feat, Phelps again found herself ...

The periodic table traditionally taught in textbooks, which organizes elements based on chemical traits such as reactivity, places helium in the rightmost column with the other less reactive elements.