Scerri is a funny guy and a fair teacher. I just hate chemistry so much. Got a C+ in the class but that's my own fault for sleeping in class and not taking the class seriously. Still a pretty cool guy though, great sense of humor but a pretty damn large ego. I would advise taking another teacher though because Scerri teaches Chem 20A in a very conceptual way that doesn't quite prepare you for computational heavy Chem 20B taught by most other professors at UCLA. If you can get Scerri for both Chem 20A and 20B then by all means, take it. It'd probably be easier than the other professors. But if you're a chem/biochem major, perhaps you'd be better off in the long run with another professor.

I had Scerri for CHEM 20A and I thought he was great.

Lecture: Like everyone has said, he teaches everything conceptually, which he is very very good at. He concentrates on ideas instead of math. I liked that he covered a wide range of topics. He is required to teach you quantum mechanics, but he expands on other stuff, like isomerism, crystal field theory, and a little bit of organic chem. He exposes you to a lot of different things.

Exams: Honestly, if you memorize the course reader, exams won't be hard. Everything in the course reader is fair game, no outside stuff. Don't be afraid to question things on the exams like typos and stuff. They say he writes his exams the night before, so be careful if something looks funny.

Course Reader: This was the only thing I had beef with. He charges you roughly $65 for the course reader. He makes the font obnoxiously large so there are a lot of pages, so he can charge a lot. Seriously, it could be condensed into a single volume.

He will diss you in front of the whole class if you say something stupid. Don't screw around. If you can get past his personality, you'll do just fine.

I would recommend.

Professor Scerri is pretty good. You only need to buy the course reader, NOT a $150 textbook or his book about the periodic table, so that's a plus.

He's a good lecturer, truly understands what he's taking about and explains well. His tests are about understanding the material. Just pay attention in class, read the course reader, and go to discussion and you'll be fine.

A downside is his personality. Very arrogant and insults you if you ask a dumb question (sad for you, but hilarious for the rest of the class). Just ask your TA questions.

The best thing about this class: it's relatively easy. All you need to do is study the course reader (you need to study it REALLY well, though) and you'll be fine for the tests. The thinkwell quizzes are annoying but they are pretty helpful. His other homeworks aren't that hard. Also, he has past exams included in the course reader, a lot of them, which are really really helpful. A lot of them are repeated too.
The worst thing about this class: He's not that good at teaching and doesn't know what he's talking about sometimes. During the first half of the class, with the quantum mechanics, he teaches it really confusingly and with a lot of holes and freaks the students out. You don't really need to learn much QM for the tests though - just the main points, and you can find these by looking at past exams. He's pretty arrogant and so is not that concerned or available, but he does still let the students know what they need to know for the tests. Basically, this class is pretty easy if you study the course reader back to front.

Had him for 20A. He is a little arrogant and mixed to many topics in an introductory course. The course reader he used is kind of disorganized, which makes it not very effective to review at the end of the quarter. Learnt the second part of the course almost by myself.

Coolest professor I ever had! If you have to take 20A for your engineering preparation or GE fulfillment, believe me, he's your best choice!

Scerri explains material clearly and makes the class not so boring with his jokes.

Just a warning: this class is very easy, but the curve is VERY HIGH. A small error on your test can bring your grade down to a B due to the extraordinarily high curve.

pretty good

http://www.youtube.com/watch?v=i3o1BXolAv0

Chem 20A with Scerri centers around his course reader. There is supplementary material on Thinkwell, which he will require you to register for as some of your homework (online quizzes) will come from the website. This is a huge plus because the online lectures are remarkably helpful and illuminate the concepts far better and quicker than a textbook might. Furthermore, every lecture is webcast so you needn't go to class. Admittedly, the camerawork could use some improvement, but it beats taking 15 minutes to walk to class and another 15 minutes walking back to your dorm.

As for the material itself, I found that the way it is presented in the course reader makes it easy to digest. The optional Oxtoby textbook is unnecessary because the tests, quizzes, and homework will have problems pulled from Thinkwell and your course reader. There were no trick questions or curveballs. Perhaps the most important thing to do has already been mentioned in many reviews: MEMORIZE THE COURSE READER!!!! Let me say that again: MEMORIZES THE COURSE READER!!!!

I didn't go to office hours and I hardly went to lecture, so I can't comment on Scerri's availability. I do know he has a fantastic, if a bit sardonic, sense of humor.

Overall, I ended up with an A+. This class is VERY manageable and does not require an excessive amount of work. I highly recommend Scerri!