Wednesday, December 21, 2022 - RHENIUM, the metal that *nobody* has heard of 😀

A highly educational Wednesday crossword, with a slew of TIL (Today I Learned) entries, including the fascinating 9D, Metal next to tungsten on the periodic table, RHENIUM, which neither Jean nor Mike, in spite of having taken several chemistry classes, had ever heard of. It is true that a number of heavier elements have been added to the periodic table, um, periodically, but the lower numbered elements have generally remained unchanged. There were some other TILs, so to help improve your, o...