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Dibs Fall 2026

CHEM 20B

Chemical Energetics and Change

Lecture, three hours; discussion, one hour. Enforced requisites: course 14A or 14AE or 20A or 20AH, and Mathematics 31A, with grades of C- or better. Enforced corequisite: Mathematics 31B. Second term of general chemistry. Intermolecular forces and organization, phase behavior, chemical thermodynamics, solutions, equilibria, reaction rates and laws. P/NP or letter grading.

Course statistics

Predicted GPA
3.25
n = 2,706 · 8 terms · ± 0.011
A range
52%
of letter grades
Taken P/NP
0%
67% of those passed
D / F / W
5.0%
incl. withdrawals

Sections in Fall 2026

Not offered in Fall 2026.

Enrollment history

Final enrollment per term, averaged across that term's sections. Four years deep, summer excluded. Per-section live curves are on each section page.

  • 23922W
  • 18622S
  • 23423W
  • 13223S
  • 24824W
  • 19424S
  • 12625S
Enrolment by term: 22W 239, 22S 186, 23W 234, 23S 132, 24W 248, 24S 194, 25S 126
Peak 248 Most recent 126 in 25S 7 terms on record

Grade distribution

  • A+ 459 · 16.8%
  • A 649 · 23.7%
  • A- 290 · 10.6%
  • B+ 330 · 12.0%
  • B 298 · 10.9%
  • B- 168 · 6.1%
  • C+ 145 · 5.3%
  • C 144 · 5.3%
  • C- 89 · 3.2%
  • D+ 13 · 0.5%
  • D 53 · 1.9%
  • D- 9 · 0.3%
  • F 59 · 2.2%
  • P 8 · 0.3%
  • NP 4 · 0.1%
  • I 22 · 0.8%

Grey bars are non-letter outcomes — P/NP, S/U, incompletes. 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 Raw n Terms A range
BARR, KRISTOPHER KENT 3.21 3.21 1,245 4 46%
RESLAN, RANDA 3.05 3.04 689 2 45%
WU, ERIC C 3.57 3.57 647 1 71%
WEISS, PAUL S 3.09 3.08 125 1 42%

“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.

By term