CHEM 20A
Chemical Structure
Lecture and discussion.
Summer Session A 2026: 1 lecture and 2 discussions. All of them are open. The oldest of these readings was 35 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. 3 of those terms are summer sessions, and summer sessions are counted here. Every instructor is pooled here. The table below splits them, and term averages across those 12 terms ran 3.08 to 3.85.
- A+ 1,001 · 22.5%
- A 1,423 · 31.9%
- A- 654 · 14.7%
- B+ 375 · 8.4%
- B 324 · 7.3%
- B- 191 · 4.3%
- C+ 166 · 3.7%
- C 109 · 2.4%
- C- 84 · 1.9%
- D+ 12 · 0.3%
- D 26 · 0.6%
- D- 7 · 0.2%
- F 85 · 1.9%
- P 9 of 4,498
- NP 6 of 4,498
- I 26 of 4,498
Percentages are of the 4,457 letter grades. Grey bars are non-letter outcomes: passes (P), no-passes (NP), and incompletes (I). They are excluded from the GPA entirely rather than scored, because counting a P as a 4.0 would be a fabrication.
By instructor
| Instructor | Predicted GPA | Raw | n | Terms | A range | Workload | Summer Session A 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 |
“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.
dibs measures outcomes: grades, seats, how fast a class fills. For what a class is like to sit in, BruinWalk has the reviews.
What comes first
dibs has not read a class page for CHEM 20A, so it cannot say what comes before it.
Counted in courses rather than quarters: dibs does not know which of them a department lets you take together.
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 Summer Session A 2026
You enroll in the discussion, not the lecture, so a discussion's status is the one that decides whether you get in. A lecture can read open while every discussion under it is full.
Seat counts as of : the oldest of these 3 readings. That term is over, so nothing has moved since.
-
Lec 1 MWF 9:00am-10:50amOpen3.51course average · 4,457 grades
9 seats left. 91 of 100 enrolled -
not checked yet2 discussions, all open.
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.
Seats over time in Summer Session A 2026
How each lecture has filled since dibs first saw it.
Lec 1 · Reslan, R. · 91 of 100 enrolled
Unchanged over 2 minutes
Both readings say 91 of 100.
Across the 1 hour from 2 Sep 03:05 to 2 Sep 03:06, dibs holds a read record for 1 of them. Every hour plotted carries a read, so a flat run here means checked and unchanged.