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CHEM 20A · Lec 2

Chemical Structure

Fall 2026Schwartz, B.J. and Casas, A.M.4 units

Seats, time, final and grades

Seats

Waitlist, 5 of 8 places taken.

435 of 435 enrolled, lecture and all discussions summed.

Meets

MWF 10:00am-10:50am

Lecture only. You also attend a discussion, listed below.

Final

Tue 8 Dec, 8:00am to 11:00am

One exam for the whole class, Los Angeles time.

Read 3 hours ago.

Grades

3.51
predicted, all instructors · 4,457 grades

4,457 letter grades, everyone who has taught CHEM 20A.

Read 2 hours ago. The latest refresh is overdue. Seats and instructors may have changed since. Check the registrar before enrolling.

dibs has seen this section open 7 times since 17 August. The last time was 28 September. 4 of those were readings where the capacity figure moved and the enrolled count did not, so dibs could not tell whether a seat existed and did not send an alert.

Join the waitlist on the registrar (opens in a new tab) Sign in to watch for an opening

Watching is the one thing here that needs an account, because an alert needs somewhere to go. Everything else on this page works signed out.

Put this class on a board

A board is one quarter you are drafting, so it needs an account to live in. Signing in brings you straight back to this page, with this class still in front of you.

Before you can enroll

From the registrar limited early, then open

Any student attempting to save or sell a spot for another student is violating Student Conduct Code 102.23d and may be referred to the Office of the Dean of Students. Seats are held for entering students who enroll through New Student Orientation sessions beginning July 2, 2026. New student restrictions will be lifted on September 15, 2026 at 8 a.m. PTE numbers are NOT available; do not contact the instructor for a PTE number.

The limit stands until 15 September, and lifts then. dibs still counts this class as one you can take, but not yet.

Restrictions read 3 hours ago.

Discussions

You enroll in the discussion, not the lecture, so the seat figure above is the sum across all of them and can read open while every discussion you could actually join is full.

8 discussions, none open. The way in is the lecture's waitlist, at 5 of 8.

No discussion is open. 3 discussions have a waitlist with room. A place on one is not a seat: it is a queue the department may or may not clear.
  • Dis 2A

    T 9:00am-9:50am

    Kim, J.

    Waitlist, 0 of 1 places taken.

  • Dis 2B

    T 12:00pm-12:50pm

    Ullrich, R.A.

    Waitlist, 0 of 1 places taken.

  • Dis 2C

    W 1:00pm-1:50pm

    Zhang, A.

    Waitlist, 0 of 1 places taken.

  • Dis 2D

    W 3:00pm-3:50pm

    Zhang, A.

    Closed.

  • Dis 2E

    R 9:00am-9:50am

    Ullrich, R.A.

    Closed.

  • Dis 2F

    R 10:00am-10:50am

    Kim, J.

    Closed.

  • Dis 2G

    F 11:00am-11:50am

    Slimp, A.P.

    Closed.

  • Dis 2H

    F 12:00pm-12:50pm

    Park, C.

    Closed.

When it meets

Mon
Tue
Wed
Thu
Fri
6am
7am
8am
9am
10am
11am
12pm
1pm
2pm
3pm
4pm
5pm
6pm
7pm
8pm
9pm
10pm

Meets: MWF 10:00am-10:50am

Moore Hall 100

Grades

3.51
predicted, all instructors · 4,457 grades

Of the 6 other people in the grade record for CHEM 20A, the 2 with the most grades: KAVNER, ABBY at 3.70 over 1,625 grades and SHAO, HUILING at 3.54 over 1,031 grades.

A range
69%
P/NP
<1%
D/F/W
2.9%

Full grade history for CHEM 20A

What students say

dibs measures outcomes: grades, seats, how fast it fills. For what the class is actually like to sit in, BruinWalk has the reviews.

Workload, heavy. 2.0 of 5 for Benjamin Schwartz, where 5 is lightest. Read 30 days ago.

What the work looks like

  • Exams mentioned, no number given, said by 11 reviewers
  • Quizzes mentioned, no number given, said by 3 reviewers
  • Papers mentioned, no number given, said by 1 reviewer
  • Problem sets mentioned, no number given, said by 5 reviewers
  • Presentations mentioned, no number given, said by 1 reviewer

Read from 336 reviews about 1 month ago. dibs counts only what a review actually states, so a kind of work nobody mentioned is absent rather than zero.

CHEM 20A reviews for Benjamin Schwartz, one of 2 listed Reviews for all professors of CHEM 20A

Will it still be here

high risk chance of closing before your enrollment pass.

Final enrollment per term from four years of grade data. Summer excluded: different population, different pass structure.

  • 29521F
  • 23122W
  • 30422F
  • 21423W
  • 29223F
  • 22924W
  • 35124F
  • 24525W
  • 39225F
Enrollment by term: 21F 295, 22W 231, 22F 304, 23W 214, 23F 292, 24W 229, 24F 351, 25W 245, 25F 392

Peak 392 · most recent 25F at 392

Seats over time

Nothing read since 1 Oct, 2 hours ago. Over about 2 months before that, filled by 142.

7 times reopened
435 of 435 · no seats left in its discussions
17 Aug 12:329 Sep 02:031 Oct 15:34 · 2 hours ago
dibs read 168 of the 507 hours its hourly record covers, 33%, and did not look in 339. dibs had no hourly record before 10 Sep, which is the other 577 of 1084 plotted.435 of 435 enrolled at the newest reading, 2 hours ago, and no seats left in its discussions. Seats from 17 Aug 12:32 to 1 Oct 15:34, 293 to 435. dibs read 168 of the 507 hours its hourly record here covers, 33%. An hour marked as read confirms a check, not continuous monitoring. That check recorded no change; changes between checks may be missed. For 339 hours dibs was keeping a record and did not reach this section. Nothing before 10 September at 13:00, where this section's record starts, has a read either way, which is 577 hours of this window. Where the drawing is faint or broken, that never means the readings are doubtful. It means the stretch between them is unaccounted for.

A dot is a reading where something moved: the seat count, the status, or the waitlist. Flat between dots joins recorded counts; changes between reads may be missed. The line starts when dibs first saw this section rather than reaching back before it existed. The last one is the last time dibs read this section, moved or not, and that was 2 hours ago. It is where the line stops, not where the count is now.

Show the readings (61)
Recorded Enrolled Capacity Status Waitlist Hours read
1 Oct 15:34 435 435 waitlist 5 of 8 6 of 16
1 Oct 00:22 435 435 waitlist 5 of 8 7 of 21
30 Sep 04:12 435 435 waitlist 6 of 8 2 of 5
30 Sep 00:02 435 435 waitlist 3 of 8 2 of 5
29 Sep 20:32 435 435 waitlist 6 of 8 6 of 16
29 Sep 05:02 435 435 waitlist 3 of 8 4 of 12
28 Sep 18:32 434 435 open 4 of 8 2 of 4
28 Sep 15:02 435 435 waitlist 4 of 8 4 of 12
28 Sep 04:32 435 435 waitlist 5 of 8 2 of 4
28 Sep 01:02 435 435 waitlist 6 of 8 27 of 91
24 Sep 07:42 435 435 closed 8 of 8 2 of 4
24 Sep 04:12 435 435 waitlist 7 of 8 2 of 6
23 Sep 23:42 435 435 closed 8 of 8 2 of 4
23 Sep 20:32 435 435 waitlist 7 of 8 2 of 5
23 Sep 16:42 435 435 closed 8 of 8 3 of 7
23 Sep 10:22 435 435 waitlist 7 of 8 4 of 11
23 Sep 00:22 435 435 closed 8 of 8 2 of 5
22 Sep 20:52 435 435 waitlist 7 of 8 14 of 41
21 Sep 04:42 435 435 closed 8 of 8 3 of 8
20 Sep 21:42 435 435 waitlist 7 of 8 2 of 3
20 Sep 19:22 435 435 closed 8 of 8 2 of 4
20 Sep 16:52 435 435 waitlist 7 of 8 11 of 32
19 Sep 09:42 435 435 closed 8 of 8 4 of 10
19 Sep 00:32 435 435 waitlist 7 of 8 30 of 86
15 Sep 11:32 435 435 closed 8 of 8 2 of 5
15 Sep 07:42 433 435 open 0 of 8 6 of 19
14 Sep 13:52 433 435 open - 20 of 61
12 Sep 01:22 432 435 open - 3 of 5
11 Sep 21:32 410 435 open - 2 of 2
11 Sep 20:52 430 435 open - 2 of 2
11 Sep 19:26 411 435 open - 3 of 5
11 Sep 15:40 410 435 open - 2 of 3
11 Sep 13:40 411 435 open - 8 of 12
11 Sep 02:40 410 435 open - 2 of 4
10 Sep 23:40 410 414 open - 4 of 7
10 Sep 17:40 410 435 open - 2 of 2
10 Sep 16:40 410 414 open - 3 of 4
10 Sep 13:40 410 435 open - 1 of 13, 12 no hourly record
10 Sep 01:40 410 414 open - no hourly record
9 Sep 01:40 393 414 open - no hourly record
9 Sep 00:40 393 395 open - no hourly record
8 Sep 22:40 393 414 open - no hourly record
5 Sep 02:40 393 395 open - no hourly record
3 Sep 23:40 374 395 open - no hourly record
3 Sep 21:40 374 374 closed - no hourly record
3 Sep 11:27 374 395 open - no hourly record
26 Aug 00:40 374 374 closed - no hourly record
25 Aug 23:40 333 360 open - no hourly record
25 Aug 20:55 374 374 closed - no hourly record
25 Aug 19:55 333 360 open - no hourly record
25 Aug 19:40 374 374 closed - no hourly record
24 Aug 16:55 333 360 open - no hourly record
24 Aug 13:55 333 334 open - no hourly record
24 Aug 12:55 333 360 open - no hourly record
23 Aug 01:55 333 334 open - no hourly record
21 Aug 02:55 332 334 open - no hourly record
20 Aug 17:55 333 334 open - no hourly record
19 Aug 14:55 293 320 open - no hourly record
19 Aug 12:55 293 293 closed - no hourly record
19 Aug 10:55 293 320 open - no hourly record
17 Aug 12:32 293 293 closed - -
How readings and alerts work

A reading and an hourly record are different things, and most charts here hold more of the second missing than present. dibs has taken readings of a section since long before it began keeping an hour-by-hour log of when it looked, so the empty stretches are dibs saying it was not keeping that log yet, not that it looked and found nothing. That is the age of the record and not a fault.

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.

Class chat

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