Stay away, by all means, stay away. This man is NOT accommodating during COVID at all. That just tells a lot of how he acts in class. He's rude and notorious for always being like that, his lectures are unclear and he does not like questions. He is the stereotypical horrible professor you think you might get.
The other reviews mention he uses old test questions, which he does. But this quarter he purposefully made his tests way more difficult because he didn't like that most of his students were getting As. He also grades on a backwards curve, which limits how many people get an A.

Just don't take his class.

I would not recommend to take this class with Scerri unless you absolutely have to. The grade is divided 30% for sapling quizzes, 30% for the midterm, and 40% for the final. The class is essentially asynchronous and I ended up watching all of the lectures on 1.5 or 2 speed the next day. The lectures only consisted of him reading through the (already posted) lecture slides but, occasionally, he would add new information or complain about how few people had their cameras on.
There are 5 sapling quizzes, all due at the end of the quarter. The questions come from the textbook and there was some overlap to the class content, but just as much content was never introduced during lecture. I would not recommend reading the textbook or doing the practice problems because there is just too much of a disconnect from the actual, tested class content.
The midterm and the final were excessively long and tedious. If you took AP Chem, the midterm should not be too difficult but towards the end of the course there is a good amount of new material that you will have to study in depth. Thankfully Scerri posted practice tests that were in the same format as both exams which were helpful for studying for the exams. Discussion was not mandatory, but I wish I went more often since the TAs essentially review the material from the past week. You can go to any section so I would recommend asking around to see which TA is the best.

I don't recommend this class to anyone who wants to maintain an interest in chemistry. If you have to take this class with him here is the rundown:
HOMEWORK: As of Winter 2020 he uses OWL for homework. It 's like 10 online "quizzes". All the homework is due at the end of the quarter and it's free points basically because they give you 10 tries on the same with different numbers/elements and tell you how to get the answer if you get it wrong. Unlimited time on every "quiz".
TEXTBOOK: There is a textbook that comes with OWL. I never used it.
LECTURES: Possibly the worst part of the class. Not bruincasted, and he posts the Powerpoints but they make no sense. Like actually ZERO sense. Worst formatting on earth, barely any insightful content. When he goes through them in class, there is slightly more clarity. Slightly. He is not a great explainer for complex topics, moves rather fast for no reason, and does not answer questions well. After the first midterm (Week 3), I stopped taking notes and attended intermittently.
TESTS: These are his only saving grace LMAO. Purely based on previous tests. Your TAs should give you a packet of his previous exams. LITERALLY just do these and memorize them and tests are a breeze. Only caveat is most of them do not have the answers so check with someone or ask your TAs if you want.
TAs: I believe this is where you'll get the most actual learning. My TA was not that great, so I attended other TA sections. They can be pretty helpful and are usually better teachers than Scerri himself. If you don't life your TA, DEFINITELY try the others. Attendance didn't really matter at all.

TLDR; don't take this class. if you have to just make sure you go to TA sections and do the past exams.

This class gave me PTSD (Post Traumatic Scerri Disorder). Professor Scerri is the worst professor I have EVER had. This class left me defeated, confused, and unprepared. This class is so hard, and there is so little support for students. This class is the only reason why my GPA dropped - I was a straight A student until now. We weren't given enough time for exams, and they had parts a-e for every question. Absolute hell. Not to mention that the answer keys weren't even correct and we could barely get clarification or corrections from both the prof and TAs. Grading of the midterm was inconsistent too, and many students reported that their final grades were curved DOWN. Like what even??? Scerri is also a very passive aggressive individual and there were some instances where he was rude and discouraging to students who had genuine questions. Unless you somehow got on his good side, he would treat you with very little respect. I had him for 14A as well (in person) and I wish I learned the first time around to stay far away from his class. Honestly, just get a good tutor or PLF because you'll learn jack from him. I relied on YouTube chemistry tutorials and explanations to get by. If you take this class, Lord have mercy on your soul, because you're going to need it.

Overall, I think the only drawback of the way that Dr. Scerri teaches is that he grades the class on the curve, which can be difficult for students in a class like chemistry. Otherwise, I thought he did a good job of getting students to understand why we are learning certain methods and equations, and while some people complain about his attaching history in his lectures, I think it is because they received a bad grade. This history helps you understand what those scientists were thinking when they came up with their theories, and you are more likely to remember it. He also has jokes!

My biggest piece of advice to do well in this class is to GO TO DISCUSSION SECTION WITH YOUSIF. He opens it up to everyone and you can go to any of the available times he has them. They were incredibly helpful and he cleared up concepts that were explained in convoluted ways in class. ALSO, if you go to class and discussion you should do well on the tests because every single problem on the midterm and final comes straight from the slides.

Aside from that, I really don't think Scerri is as bad as the reviews say. I took the class fall 2021 with the expectation he would be a completely unfair grader and horrible lecturer with a 2.9 rating on bruinwalk. Maybe it was because it was online, but the class was very easy to follow along and take notes on. Sometimes Scerri wouldn't answer a question adequately or explain a concept in a way that would just confuse people, but for the most part, I feel like I sufficiently learned all CHEM 14B topics .

Lastly, Achieve quizzes. For the quizzes, I had done 2 of them prior and I did the last 5 from 10pm to 9am the day they were due without any distractions, so that should give you an idea of how to space them out/how much to procrastinate.

Chem 17 offers a lot of help for first timers in Chemistry, but also is insanely quick. Scerri covered 11-12 topics in the 10 weeks and, in truth, missing a class or dropping out of focus for a minute can put you behind. I heavily recommend attending his office hours (the ones he holds in the morning I found work best for 1 on 1 time with the professor). The classwork is light, with four online quizzes that are open everything (book, professor, classmate, internet, and can be taken three times with the highest score being in the gradebook) and two graded homework assignments from the textbook. There is one midterm. If the pace scares you, I still recommend taking this class. It absolutely helps with understanding the subject and opens doors for attending professor and TA office hours.

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.

Okay here's the thing.

Scerri is a terrible teacher. His lectures are disorganized and confusing, and he's not exactly eager to help students. HOWEVER . . . his exams are very predictable and easy to study for, and he grades entirely on a curve which really helped me out.

My recommendation? Take this class with him, but don't expect lecture to help you. Watch Professor Dave Explains on Youtube and study off past exams. You'll be fine.

If you have had him for 14A the grade breakdown is identical. 30% thinkwell, 30% midterm, and 40% final. I opted out of the final due to everything that went down during the end of spring quarter..

Scerri comes off as a very arrogant, know-it-all professor, granted I am sure he is incredibly knowledgeable but he likes to say words like "elementary" when describing certain concepts which just comes off condescending. I wouldn't say he is the worst professor I have had, but he is not near the top of the list. I did well in both of his chem classes because the problems he does in class are nearly identical to the problems on the midterm/final.

The best thing to do in this class is honestly rewrite notes to get a better understanding for yourself. Scerri is not the clearest, and you will most likely be confused by his lectures due to the disorganized structure and his poor way of teaching.

Otherwise, I did generally learn a lot from 14A and 14B but I am incredibly glad to be over with Scerri.