When your 6 yo wonders aloud if his elementary school principal will allow him to start an "elements of the periodic table" club so that all the other kids who love the periodic table can get together and just talk about the elements.
My DS6 would love to join a club like that, too. He has all of the Theodore Gray element books and cards, a poster of the periodic table, and we just bought the periodic table shower curtain, too. He's loved the elements since he was three and LOVES to discuss them and their properties.
He recently discovered a Nova special about the elements on Netflix, and was overjoyed!