I'll do my best to give a fair, comprehensive evaluation. Here's a bit of background where I am coming from:
Grade: A.
Bioengineering Major.
Relevant High School Coursework: 5 in AP Chem, a 5 in AP Physics.

That being said, Scerri's class was definitely a challenge but doable.

Class lectures: Overall, Scerri does a decent job teaching. He is a fair teacher, but what throws off many of his students is the fact that his lectures are supremely conceptual, while his tests are primarily computational (of a sort). During lecture he goes over concept over concept but does very little practice problems. That being said, there is so much content being said during lectures, many of which is not in the course reader. In order to have true success in the class, it is not enough just to attend lectures but to take meticulous notes. One detail he might say may be covered verbally but it might be key on the actual exam. Even though he has a course reader, there was stuff covered that he had to use seperate slides (not in the course reader). Though this content seems extra, take it seriously, download it when he sends it in an email, print it out, and put it along with the stuff you want to study. On our final for Fall 2013 he had content he had barely grazed over.

Secondly, do your best to attend lectures. Though he does give podcasts and an excuse not to arrive, sometimes stuff happens to the podcast that makes it cutoff some of the lecture. Other times the camera angle does not capture things he writes on the board.

Studying for Midterms and Exams: Personally, people say to memorize the course reader as if section by section. The best way to prepare for the course is taking the big concepts and linking them all together, filling the holes with the details from his lectures, rather than memorizing them forthright. If you can connect all the concepts together and use each one to memorize another, you will have a much easier time than memorizing them fact by fact. One example of this is how he arranges all the content up to the Midterm. Rather than memorizing each theory up to Schroedinger's equation in preparation for the midterm, it is better to study with the guiding question of "how does all the content that I have learned build up to the prevailing theory of Quantum Mechanics and Schroedinger's Equation?" Arranging the course and the content through a series of large and smaller questions will make the whole course of CHEM 20A cohesive and you will get a better understanding with less studying. Linking concepts of the course rather than memorizing each piece by piece will be beneficial.

In the course reader, Scerri provides a number of practice exams. For a SOLID GRADE in the course, the best thing to do is to know every singe problem in the practice tests. His midterm and final mimic the finals and midterms he gives in the past (shocking, right?). When it comes to doing these problems, it can't be a matter of going through each practice exam once and being done with it. You really must practice the problems that give you the most difficulty if you want to succeed. Another important thing is to try these practice exams at least a couple weeks before the actual final. Start studying week 8 or 9 with these practice finals for a couple reasons: Firstly, he gives a lot of practice exams. Secondly, each practice exam takes at least a 2-3 hours to complete if you are studying correctly. Starting these practice tests the weekend before Finals Week will be utter hell.

Lastly, study with the right people. That is what helped me most in the course. Whatever holes regarding one person has can be easily covered by the other. This will help you immensely in studying the for the midterm, the final and those pesky Thinkwell Quizzes. One note regarding Thinkwell quizzes. Their questions are not nearly as hard as the exam, but do them with friends and you will likely get an A since questions are recycled and you can take the quiz 3 times. Take it all three times even if you do get a 100 for mastery of content. Again, group work will help manipulate the system to your advantage.

Discussion Sections and Office Hours: When it comes to discussion sections, dominate the section with questions. Get these questions from stuff you don't understand from notes, or from the practice exams (another reason why you should be starting these practice exams early). Everyone else will not have questions until weeks 9 to 10, by then it is too late. Take advantage of everyone else's complacency during the early weeks to have all your questions from the practice exam answered. You will be much less stressed. If you are to attend office hours, again be the one to ask questions about content. Likely whatever questions you may have are the same ones others may ask, but if someone else asks the question, there is a possibility of being stuck there for another 10 minutes listening to content you already know.

Misc: Scerri has a decent class. He is a funny professor whose arrogance can come off as amusing and somewhat charming. Get him to play his guitar and you'll be listening to him jam away. Quite impressive really, but we all know he's playing for the ratchets. Be the one to ask the questions and answer the questions. One warning when talking to Scerri however: don't be stupid when talking to him. He ostracized one kid for saying "like" too much. Poor kid. If you have decent grammar skills and aren't too socially awkward (thats for you engineers), then you should be fine in navigating Scerri's sharky waters. Best of luck.

I agree with what people said below. Just make sure to include EVERY detail on the test. That makes all the difference. You may know the problem like the back of your hand, but if you leave out some minor detail, they leave out some major points. Oh, and make sure you have a good TA.

Great lecturer and great class . Took it my first quarter at UCLA and it was interesting and a perfect introduction to the classes here. Tests arent hard at all, just use his course readers and the pages he assigns from the textbook

I am selling my textbook Principles of Modern Chemistry by Oxtoby. No notes or highlights, and in mint condition. Text me at ********** I can meet on or around campus. Selling for $60 with price negotiable.

This guy caused so much anxiety for my dear roommate I needed to report it, he sucks so bad, don’t take him he is the worst

gave us a final and midterm on Sunday :( he is actually an evil scientist. he walks like gru from minions but he's not as cool. i swear I'm smarter than a minion...this jerk curves down like wtf.

The way to "beat" this class and get a B+ or above seemed pretty easy in the beginning. Assignments were a guaranteed 30% (although they covered nothing on the exams), Midterms and Final had practice exams to study from, and the class was recorded so taking notes at 1.5x speed and having the ability to pause whenever to search something up was nice. That was until grading was arbitrarily "curved down." Scerri mentioned in the syllabus that there wouldn't be a curve but that cut-offs would be adjusted... but I did not expect him to bs the grading scheme.

To put things into perspective, a % overall of 91.8 results in an A-... wouldn't that make 89.25% a B+? Maybe a B if we're being really strict here. No, instead it is a B-!! That's crazy!! Everybody is saying that scores were curved down but nobody brings up that the syllabus literally mentions that they wouldn't be! 2.6% apparently is a whole letter grade's worth. That's only 13 points on the final.

Moreover, when you email Scerri about the details of the grade cut-offs (or anything to be honest), all you will likely get is a rude response saying no. I mostly had compliments for this guy until my grade came about and I suggest you don't fall for the same trap. AVOID THIS GUY.

Not the devil incarnate, but not very good either. TAs are a saving grace; I would just stare blankly at him during lecture until discussion when everything would finally comprehend. Only went to my specific TA session, but obviously go to more if you need more practice. Never went to office hours because I generally don't want to see him more than necessary so I can't comment on the helpfulness of that. Basically just reads off posted slides during lectures (which are recorded and aren't mandatory).
Attendance for both lecture and discussion was entirely optional, but probably go idk. There were only three assignments in the gradebook and the final class grade ended up getting curved down :(( Exams aren't the worst thing in the world, but the material (especially FRQ) is mostly writing about specific things from his slides and not just calculations and practice problem-style (i.e. had to draw different historical versions of the periodic table).
The only other assignment were online quizzes that were basically free points since you got 10 tries and they would tell you exactly how to solve if you got it wrong, and even if you got it wrong 6 times before getting the right answer, you'd still get a 100% for the problem. Obviously do those and try to keep up with them as the class moves along in the quarter (there were people talking about not even having started, like, five hours before they were all due bestie what are you doing) because (1) again, free points and (2) semi helpful for practice (although they are mostly calculation-based rather than his exam style).
Sometimes Scerri is a little silly and fun guy during class, but he also passive-aggressively attacks people sometimes.

This guy can not teach to save his life. The TA’s literally were taking pictures of his slides themselves and he wrote the wrong answer for the slides most of the time. The tests are bs and so are the lectures. He his a pretty cool guy but definitely not a cool teacher. Also whatever grade you get according to the syllabus he drops a letter grade for your final grade.

This was the hardest class I’ve taken this quarter. All of my other classes I’ve performed extremely well in while taking this class I was hoping to just pass. If you don’t have any background in Chem you will DEFINITELY STRUGGLE. I didn’t take AP chem and I had to catch up so much. Even if you did take AP Chem, friends I had in this class struggled towards the second half of the quarter. Scerri is really unhelpful and the most you can do is seek help from the TA’s. I studied so much towards the second half of the quarter to make up for my bad midterm score and landed with a C. So long as I don’t have to retake this class ever again.

Scerri is like love him or hate him, tbh the class isn’t that hard, and if ur a diligent student an A is very much obtainable. I have zero background in chemistry, slept during lecture, and crammed everything days before tests, so Im not really disappointed in my grade

Scerri is the cockiest man alive, flexes his books during lecture, and has the worst lecture slides Ive ever seen. My ta and classmates def carried me through this class. Would never take again, but then I again, I also hate chemistry in general.

Tests are fairly simple, he curves everyone to a B-, an A on the midterm was a 90/94. If u dont do things last minute and keep up w material the class should be pretty easy