Want to hear a joke about potassium? K. Want to hear one about sodium? Na.
Today's theme features the 151-year old Periodic Table. It seemed to me that the clearest way to explicate the science-based theme was with equations. Thus:
Clue = Element symbol + word + ?
Answer = [Element name represented by symbol spelled out] + synonym for additional word = common item or adjective.
Example: 43A: Aground? Ag is the symbol for silver and 'bullet' is a synonym for a round QED: the answer is SILVERBULLET.
My favorite was OXYGENSUPPLY for Oration? - ha! It reminds me of the old ads for Ken-L Ration. Anybody remember those?
It took me rather too long to solve the equation, but I finally figured it out with IRONMAN (Female?) when I had IRO_MAN. :)
I had some trouble in the southwest. I got the CARBON for the C in "Cold?" at 57A, but I lead myself astray trying to fit AgED or AgEr at the end for 'old', completely overlooking the D. It was a NOgO until I thought of HATER for "Curmudgeonly sort." Then, BOOMt!