I recall in a rather critical "oral exam" I endured, the very first question was "Why do atoms bond into molecules?". I have a rather succinct response, which was followed by a more detailed question, and then a more detailed question, until I could no longer answer at all. It didn't take long, professors know a LOT more than students. Then ... he started giving me hints, and it dawned on me they were interested in how I could think more than what facts I could recite. Five professors, one student, rather intimidating, questions on literally any topic. You got two shots at passing, this was my first and I made it, rather remarkably I think, I had no clue how to prepare.
I had reread my freshman chemistry text book, and realized I had forgotten quite a bit, and never learned much of the rest. That really helped, I think. Another question I was asked was to write every equation I knew involving K, the capital K, as opposed to k. Interestingly, or not, K, the capital one, = little k forward divided by little k backwards.
Anyway, thermo is both interesing and confusing.
