CHEM 20A
Chemical Structure
Lecture and discussion. The registrar has published a final exam time.
Fall 2026: 2 lectures and 14 discussions. 1 lecture and 6 discussions are open. The oldest of these readings was 3 hours ago.
Grades
3.51
Average grade awarded in CHEM 20A. Not a student rating: this is what the grades were.
In the A range
69%
of the 4,457 letter grades
D, F or W
2.9%
of every letter grade awarded, plus withdrawals
Taken pass/no pass
<1%
9 of 15 students passed
The registrar's own records: 4,457 grades over 12 terms, Fall 2021 to Fall 2025. Every instructor is pooled here.
What is inside that record
3 of those terms are summer sessions, and summer sessions are counted here.
The table below splits them, and term averages across those 12 terms ran 3.08 to 3.85.
Historical grades for SCHWARTZ, BENJAMIN JOEL, across recorded terms. The course summary above includes all professors.
No grade history is available for this professor in this course.
By instructor
| Instructor | Predicted GPA | Raw | n | Terms | A range | Workload | Fall 2026 |
|---|---|---|---|---|---|---|---|
| KAVNER, ABBY reviews ↗ | 3.70 | 3.71 | 1,625 | 3 | 81% | light | not teaching it |
| SHAO, HUILING reviews ↗ | 3.54 | 3.54 | 1,031 | 3 | 68% | light | not teaching it |
| WU, ERIC C reviews ↗ | 3.37 | 3.37 | 784 | 1 | 64% | - | not teaching it |
| DEIFEL, NICHOLAS reviews ↗ | 3.65 | 3.65 | 350 | 2 | 83% | very light | not teaching it |
| OW, FRANKLIN P reviews ↗ | 3.28 | 3.26 | 336 | 3 | 53% | very light | not teaching it |
| SCERRI, ERIC ROBERT reviews ↗ | 2.88 | 2.85 | 331 | 1 | 28% | average | not teaching it |
Why Predicted is not the Raw average
“Predicted” is shrunk toward the course average, which is itself shrunk toward the department, so an instructor with a handful of students sits near the course mean rather than topping the list.
Grade records describe outcomes. For what a course is like to take, read student reviews written on dibs below or follow the separate external review link.
Workload and assignments
Reported assignments across instructors and terms. This term's syllabus may differ.
What the work looks like
- Exams mentioned, no number given, 11 mentions in past reviews
- Quizzes mentioned, no number given, 3 mentions in past reviews
- Papers mentioned, no number given, 1 mention in past reviews
- Problem sets mentioned, no number given, 5 mentions in past reviews
- Presentations mentioned, no number given, 1 mention in past reviews
Based on 336 reviews; source checked about 2 months ago. dibs counts only what a review actually states, so a kind of work nobody mentioned is absent rather than zero.
In Falls
Ran in 5 of the last 5 Falls.
From the terms dibs holds, which start in Fall 2021 and exclude summer. A department can run a course in a quarter it never has before.
From the registrar's catalog
Lecture, three hours; discussion, one hour. Preparation: high school chemistry or equivalent background and three and one half years of high school mathematics. Recommended preparation: high school physics. Requisite: completion of Chemistry Diagnostic Test. Enforced corequisite: Mathematics 31A. Not open to students with credit for course 14A. First term of general chemistry. Survey of chemical processes, quantum chemistry, atomic and molecular structure and bonding, molecular spectroscopy. P/NP or letter grading.
Sections in Fall 2026
Choose an open discussion to enroll; an open lecture alone does not mean a seat is available.
Seat counts as of : the oldest of these 16 readings. Seat readings are snapshots, not live availability. Their timestamps show when dibs last checked.
-
Seats
ClosedLecture: 350 of 350 enrolled
Instructor
Wilson, P.
3.51Predicted GPA
Historical records across all instructors; 4,457 letter gradesSeat risk
high risk6 discussions, 4 open: Dis 1A, M 1:00pm-1:50pm, Dis 1B, M 3:00pm-3:50pm, Dis 1C, W 2:00pm-2:50pm, and Dis 1D, W 4:00pm-4:50pm. Lecture reads closed, so its 4 open discussions cannot be reached from here. No waitlist listed.Every discussion, with its time and seats: 6 discussions
-
Open
1 seat left.
59 of 60 enrolled
-
Open
1 seat left.
58 of 59 enrolled
-
Open
1 seat left.
58 of 59 enrolled
-
Open
3 seats left.
55 of 58 enrolled
-
Closed
61 of 61 enrolled
-
Closed
59 of 59 enrolled
-
-
Seats
Open3 seats left in discussions.
Lecture: 434 of 435 enrolled
Instructor
Schwartz, B.J. and Casas, A.M.
3.51Predicted GPA
Historical records across all instructors; 4,457 letter gradesSeat risk
high risk8 discussions, 2 open: Dis 2C, W 1:00pm-1:50pm, and Dis 2E, R 9:00am-9:50am.Every discussion, with its time and seats: 8 discussions
-
Closed
54 of 54 enrolled
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Closed
55 of 55 enrolled
-
Open
2 seats left.
54 of 56 enrolled
-
Closed
55 of 55 enrolled
-
Open
1 seat left.
53 of 54 enrolled
-
Closed
54 of 54 enrolled
-
Closed
55 of 55 enrolled
-
Waitlist
0 of 1 places taken.
54 of 54 enrolled
-
Final enrollment, averaged across each term's sections: between 214 and 392 a term over 9 terms, summer excluded, most recently 392 in Fall 2025. That is the shape across years, not this term, which is above.
From the people who took it
Student reviews
What taking CHEM 20A was like: the work, the teaching, and what students wish they’d known.
Your experience could be the first.
No student reviews are available to read on dibs for this course yet. Took it? Tell the next person what helped, what was hard, and how you spent your time.
Looking for more perspectives?
External reviews are separate and do not count toward the dibs rating.
Seats over time in Fall 2026
How each lecture has filled since dibs first saw it. This course runs 2 lectures; the legend under the chart picks one.
A dot is a reading where something moved: the seat count, the status, or the waitlist.
What a flat run means, and where a line starts
Flat between dots means it did not drift, it held and then jumped, and a line starts when dibs first saw that lecture rather than reaching back before it existed. A lecture that has never moved draws a flat line across the whole window, and one with two or three readings draws a line joining them, which is too few to read a trend from.
Lec 1 · Wilson, P. · 350 of 350 enrolled
Nothing read since 18 Oct, 3 hours ago. Over the 2 months before that, filled by 130.
Lec 2 · Schwartz, B.J. and Casas, A.M. · 434 of 435 enrolled
Nothing read since 18 Oct, 3 hours ago. Over the 2 months before that, filled by 141.
How readings and alerts work
Dated seat counts can be available even when hourly check history is missing. Gaps do not show whether seats changed between observations.
Seat counts show the last successful read, not live availability. Refreshes can be delayed by request limits or upstream interruptions. Watched sections receive priority, but an hourly update for every section is not guaranteed.
The registrar can change a seat count between our checks. Alerts depend on dibs detecting an opening and completing delivery; a quiet watch does not prove that no seat opened. Check the registrar before enrolling.