Chemical Structure

Grades

3.51

Average grade awarded in CHEM 20A. Not a student rating: this is what the grades were. i The mean of every letter grade the registrar has published for this course, pooled across every instructor who has taught it. It is not shrunk toward anything, because a course average cannot be pulled toward itself. Standard error 0.009.

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.

By instructor

“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.

Reviews for CHEM 20A ↗

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

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 03 Sep 11:29: the oldest of these 16 readings. The registrar publishes hourly and dibs reads what it can each hour, so a row can be older than that.

• Lec 1 MWF 8:00am-8:50am

  Open

  Wilson, P.

  3.51

  course average · 4,457 grades

  21 seats left. 286 of 306 enrolled medium risk i A guess about whether this will still be here at your enrollment pass, from how full it is now and how fast classes like it have filled before. Seat risk is a prediction and seat status is what the registrar said: they are two things, and this page keeps them apart.

  standing limit limited by standing: New Students Only: restrictions read 13 hours ago

  6 discussions, all open.

  This limit is on the class, so it applies to all 6 discussions below.

  › Every discussion, with its time and seats (6)

  • Dis 1A

    M 1:00pm-1:50pm · Young Hall 2033

    Open

    2 seats left.

    50 of 52 enrolled

  • Dis 1B

    M 3:00pm-3:50pm · Young Hall 2033

    Open

    3 seats left.

    49 of 52 enrolled

  • Dis 1C

    W 2:00pm-2:50pm · Young Hall 2200

    Open

    3 seats left.

    49 of 52 enrolled

  • Dis 1D

    W 4:00pm-4:50pm · Dodd Hall 146

    Open

    3 seats left.

    49 of 52 enrolled

  • Dis 1E

    R 10:00am-10:50am · Geology Building 3656

    Open

    7 seats left.

    40 of 47 enrolled

  • Dis 1F

    R 1:00pm-1:50pm · Public Affairs Building 2250

    Open

    3 seats left.

    49 of 52 enrolled

• Lec 2 MWF 10:00am-10:50am

  Open

  Schwartz, B.J. and Casas, A.M.

  3.51

  course average · 4,457 grades

  21 seats left. 374 of 395 enrolled medium risk i A guess about whether this will still be here at your enrollment pass, from how full it is now and how fast classes like it have filled before. Seat risk is a prediction and seat status is what the registrar said: they are two things, and this page keeps them apart.

  standing limit limited by standing: New Students Only: restrictions read 13 hours ago

  8 discussions, all open.

  This limit is on the class, so it applies to all 8 discussions below.

  › Every discussion, with its time and seats (8)

  • Dis 2A

    T 9:00am-9:50am · Young Hall 2033

    Open

    2 seats left.

    47 of 49 enrolled

  • Dis 2B

    T 12:00pm-12:50pm · Young Hall 2033

    Open

    3 seats left.

    47 of 50 enrolled

  • Dis 2C

    W 1:00pm-1:50pm · Young Hall 2200

    Open

    2 seats left.

    47 of 49 enrolled

  • Dis 2D

    W 3:00pm-3:50pm · Renee and David Kaplan Hall A65

    Open

    3 seats left.

    47 of 50 enrolled

  • Dis 2E

    R 9:00am-9:50am · Boelter Hall 5249

    Open

    3 seats left.

    47 of 50 enrolled

  • Dis 2F

    R 10:00am-10:50am · Public Affairs Building 2250

    Open

    2 seats left.

    47 of 49 enrolled

  • Dis 2G

    F 11:00am-11:50am · Dodd Hall 170

    Open

    3 seats left.

    46 of 49 enrolled

  • Dis 2H

    F 12:00pm-12:50pm · Haines Hall A25

    Open

    3 seats left.

    46 of 49 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.

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.