High School Chemistry

I had a phenomenal high school chemistry teacher. I took honors chemistry as a sophomore, so it was really hard, but it was also really worth it. There were several reasons the class was memorably great, among them the extra credit opportunities available to students who wanted to present a chapter from the book (I always liked to play teacher), the teacher's amusing habit of practicing putting during our tests (he had a putting green in the front of the room), and the giant, wooden periodic table hanging on the wall in the front of the classroom. Gosh, I liked that class.
 
The two concepts I learned in that class which have stuck with me since and probably will forevermore are the following: unit/error analysis and orbital shapes.
 
If I'd taken physics first, I would have learned about unit analysis and significant digits there, but I learned it first and best from this chemistry teacher. He was very picky about sig digs (which apparently everyone else calls sig figs), which has strongly shaped my philosophy on the matter. Knowing the precision to which you know a value is extremely important! This teacher also heavily emphasized unit analysis, which I posit is one of the three most important skills for solving a physics problem, those being
--picture the situation (Faraday-style)
--order of magnitude estimate (Fermi-style)
--unit analysis.
Making sure units match and doing unit conversions are concepts which the teacher reiterated until we knew them solidly. I feel sorry for some of my peers and introductory physics lab students who were only cursorily introduced to unit analysis early on, since that's one of the major ways in which I check my answers to problems. It's fun and easy--simple algebra, multiplying and dividing by fractions equal to one--which makes for a nice change from convoluted calculations needed elsewhere in class. (As a side note, a math professor once told our engineering-oriented class that much of math consists of adding zero and multiplying by one.)
 
The second important idea I shall always remember from high school chemistry is what orbitals look like. I recall being nearly feverishly anticipatory when the teacher told us we'd be learning about quantum mechanics, only to be disappointed to find that we wouldn't be talking about the uncertainty principle but rather about atomic orbitals. Still, his visual aids for atomic orbital shapes have proved a frequent prop to my memory. He got Styrofoam balls, rings, and such, easily obtainable from craft sections in stores, painted them different colors, and shaped and glued them into the shapes of the S, P, D, and F orbitals. Whenever I encounter the terms "D orbital" or "L=2 orbital," I picture a Styrofoam construction, not some Mathematica-produced plot in a book. Sure, visual depictions of orbitals may obscure the probabilistic nature of same, but it is, to my mind, a good sight better than having merely a numerical concept of what such things mean. One of these days, I'm going to make my own set of Styrofoam orbitals.
 
In short, high school chemistry has helped me a great deal in physics, shoring up my science knowledge with some fundamental concepts which college-level classes often take for granted. That class has become my ideal (in Plato's sense) of what a high school science class should be, and I'm grateful I was lucky enough to have had that experience.