Many reviews have already captured the amount of work required for Chem 20BH. If you look at the distribution of grades, you will be able to see that, given the proper amount of effort, it is quite easy to get an A. Paul WILL reward you for trying hard, showing up to office hours (he makes a point of ensuring everyone goes), and putting effort into this class. By the end, you aren't really concerned about your grade, and it's more the skills in research and intuition that you've gained that matter.

This class is an experience that is very much worth it for people interested in going into research as a career, looking to gain advice on joining research labs, grad school, etc. It is an experience more than anything else. I would not exactly describe this class as enjoyable, but looking back I would definitively take it again; he pushes a "foreign language immersion" philosophy and in turn expects a lot from his students, including putting in tons of extra time outside of class to go to office hours, seminars, etc. beyond the arduous amount of assignments he gives. Ultimately, you could probably get by without too much pain if you just show up and put half-effort into the assignments, but then you're losing the whole point of the class. You SHOULD be kind of a try-hard in this class because then you'll get the most out of it. But, as a result, the class takes so much of your time and the "4-unit" thing is essentially irrelevant because Chem 20BH was the ONLY class I was ever truly focused on over Winter quarter, despite taking 20 units of credit.

I said multiple times over the quarter that Chem 20BH was ruining my life, that I wanted to switch majors, that I hated Chemistry, and I wasn't exactly lying; but perhaps the catharsis at the end when you turn in your final exam and feel the weight of Chem 20BH lift off your shoulders makes you realize that the class is worth it in the end.

Only take Chem 20BH if you are committed to the experience, to letting Winter Quarter be defined by this class. You have to be committed from Day 1 to the workload. But if you take the class, you will learn to love it, make meaningful relationships with Paul and your peers, and recite LAnOx and GRedCat an unhealthy amount of times. And, in the end... it's kind of an easy A.

This is a great class, I definitely recommend taking it instead of CHEM 20B if you can get it. It may be more work i'm not sure but the projects make it more interesting/applicable. I didn't find the class super stressful.

Paul is a pretty awesome professor for this class specifically, which he cares a lot about. He's also really active in helping students to get research positions. He's really enthusiastic about chemistry and he encourages his students to attend different seminars and other events frequently. You get extra credit on exams for describing research labs you've looked into and seminars you've watched. There's a lot of work (final research paper, like 3 different homework assignments due each week, doing a video presentation, etc) but overall I would totally recommend the class if you're willing to put in the work (and if the regular 20B professors that quarter are bad). Paul's tests are fair and he accepts different answers if your argument makes sense (ie: what type of spectroscopy would you use to find x thing about this molecule).

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.

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

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.

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.

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.

We can see some pretty words coming from the latest review, praising Prof.Weiss for the "challenge and tests that conceptually prod your understanding of chemistry to previously unattained depths". Indeed, the materials covered during lectures are interesting and unprecedented. However, I would like to ask the reviewer:

"Did the extra course materials compensate for the loss in materials that were supposed to be taught but not covered in lectures?"

No they didn't. Weiss didn't really discussed much about thermodynamics, acid-bases, or equilibria. As a result, you have to study them on your own by referring to the textbook, which is indeed poorly written.

As an introductory course, chem 20b is designed to prepare undergraduates for their even tougher upper division chem/engineering courses. Thanks to Weiss, I can say that over 60% of the class became underprepared.

I do not want him to overthrow this course's original aim.

This class is almost entirely about Weiss' nanotechnology research and techniques more than about what supposed to be Chem20B materials. It got three midterms - lowest one dropped, and a final. You will be tested on those research as well, along with some weird grading criteria - it is like grading an essay. There is no calculation on the tests, it is conceptual and confusing - almost like a guessing game. The way he teaches lectures is like research talks, however the students, with very little background knowledge, have to "imagine" of what he is talking about. There are some days lectures will be on Skype, which is not helpful at all. I studied countless hours and still messed up in this class. Paul Weiss is a great researcher and a nice guy, but I definitely do not recommend this professor for Chem20B. Find another professor who will make you love and enjoy Chemistry.