Professor Weiss has entirely changed 20B from the normal syllabus of the class, he assigns homework and reading from the textbook but after the first month I completely stopped doing the reading because it has NOTHING to do with what you will talk about in lecture or what you will be tested over. His teaching and testing style are the weirdest and worst I have ever encountered, you can definitely tell that he is a researcher and not a professor (he doesn't let you forget it either because he brings up all his published papers and awards and friends who are nobel laureates every five seconds). He's a nice guy, but definitely not used to teaching this large of a class at this level and it shows, I don't think he prepared me very well for 30A and I did not enjoy his class, if you can take someone else, I would highly recommend doing so.

Honestly, Weiss is a very enthusiastic person who genuinely enjoys going to lectures and even woke up at 4 in the morning one week to give skype lectures from abroad.

However, this class is really not the best place to learn anything that is in te course name "Chemical Energetics and Change". Towards the end of the first week, it was pretty apparent that the way that Weiss was teaching gas laws was overly simplified and not really helpful for students in doing the homework. In addition, he would occasionally interrupt the topic to start speaking about the various kinds of spectroscopies, which a lot of people found interesting, but it really took away from the time he could have spent teaching gas laws. Starting second week, I started going to Li's lectures because I felt that if I was going to learn anything this quarter about chemistry, it was not gonna be from this class.

I didn't know how bad the class was going to be though. Starting third week, we started thermochemistry while the homework followed the book and was on questions of phase equilibria. I think I gave up on trying to find what he talked about interesting when he went into semiconductors. It just was not what I felt that I wanted to or needed to learn from the course. When the unit got into thermodynamics, a lot of people were stuck on the harder problems because we had no idea whether to spend our time trying to keep up with what Weiss was teaching us, or to try to learn the concepts in the book to solve the homework problems.

Of course, the latter would have been very good for learning the topics we were supposed to in this course, but it probably would have killed my grade in this class. Even though the stuff we were supposed to be learning was gas laws and phase equilibria in the first 2 weeks, the first midterm (based on the first 2 weeks) largely tested the various types of spectroscopies. The second midterm, in turn largely tested electrochemistry and semiconductors while we were supposed to be learning thermodynamics. I don't think that the final had any material we were supposed to be learning in the course at all. The tests were all qualitative, usually involving very little math and mostly just describing how things work; really just regurgitating what he tells you.

The TA will probably be your lifeline in this course to doing homework and understanding either what the book tells you and what Weiss tells you. But that is also a lot of stuff to fit in 50 minutes so you should definitely go to office hours. Weiss's own office hours were actually pretty inconvenient for me and I didn't really like him anyways so I didn't go. But I heard that he doesn't really have anything that he could use to show students how to do problems; no whiteboard or chalkboard. So I guess the office hours are best for asking him questions on the lectures.

The class had 3 midterms, but everyone is allowed to drop one midterm. I really don't know how good that is if everyone gets curved at the end of the class though...

All in all, I really regret taking this professor, but I sat through Li's lectures and she completely skipped over acid-base equilibria. That is not to say that Weiss did it well, but rather that we understood that we had to self-teach ourselves it.

Professor Weiss cares more about student mastery of the material than any other professor I've had. Would definitely recommend to anyone who wants to truly master this courses's curriculum as well as material that was removed from the course.

Don't make the same mistake I did. Take that other professor.

This class was supposed to be titled "Chemical Energetics and Change"
But what actually taught by Weiss were:
x-ray photoemission spectroscopy, x-ray diffraction crystallography, flow cytometry, fluorescent in-situ hybridization, silicone polymers, biopolymers, direct and indirect-band gap semiconductors, semimetals, semi-insulating semiconductors, and so on.

And yes, as you expected, these topics are designed not just for fun - they DiD appear on the exams, which were purely conceptual (no calculators were allowed, by the way, because there were NO questions involving any quantitative calculations). While the topics that were supposed to be in the syllabus - entropy, enthalpy calculations, acid-bases, kinetics, etc. were barely covered during lectures, which appeared to as highly incoherent, disorganized and strangely paced ("flow of consciousness" should be a better term) as a typical episode from Rick and Morty - that is, you never know what's coming up next.

I would recommend Weiss to all kids who are chemo-nerds/maniacs and enjoy bragging hours after hours about nanotechnology. However, if you intend to take chem20B to gain some true, fundamental and organized knowledge of chemistry, Weiss would never be your first choice.

Prof. Weiss meets every standard for a good professor, except that his lack of organization and dabbling into sophisticated and irrelevant subjects most of the class did not understand made his class a pain in the butt for any non-bio/chem majors.