Tuff Crosswords

 Every circle in this puzzle contains a two-letter atomic symbol for a unique element.

Every down answer in this crossword is a theme entry. But wait, there's more! This crossword has a couple of BONUS themers There are two Across entries in this puzzle which conform to the theme. Can you find them?

Hope you enjoy! Here are some of the entries which unfortunately didn't make it in but which are still fun.  PHYTOPLANKTON - PLANT STRONGER - SONG (Kelly Clarkson my Beloved) BUDWEISER - BEER

A twist on a fairly common formula. Now each theme category has TWO words hidden inside it which belong to that category. Except for the last one - that has three (hence the different shading colors). Now, it's my judgment that all of the categories are reasonable entries - however if that is not your take, I do apologize, and I offer the fact that MUSICIANS has MCA and SIA (and NAS backwards) hidden in it as a consolation, as I could not fit that in the puzzle. Click to see the PDF  

This puzzle serves two goals. First, to make the fake crossword from the Community crossword credits scene a reality; second, six actual entries already implements, to cram as many Community references into the puzzle as possible.