Physical BioChemistry: BCHM 485

Spring 2026

Class meets TuTh at 9:30 am in PHYS2122
Professor: David Fushman
Office Hours (tentative): Thursdays, 5 - 6:30 pm (via zoom)
E-mail: fushman@umd.edu

Syllabus

Textbooks

Required:
Physical Chemistry: Quantum Chemistry & Spectroscopy by Thomas Engel & Philip Reid, 4th edition
Physical Chemistry: Thermodynamics, Statistical Thermodynamics, and Kinetics by Thomas Engel & Philip Reid
(The Thermodynamics textbook that you might still have from the CHEM481 course.)
Recommended:
Atkin's Physical Chemistry by Peter Atkins, Julio de Paula, James Keeler, Vol.2 Quantum Chemistry, Spectroscopy, and Statistical Thermodynamics;
Physical Chemistry with Applications to the Life Sciences by David Eisenberg and Donald Crothers;
Principles of Physical Biochemistry by van Holde, Johnson & Ho;
Molecular Driving Forces by Dill & Bromberg;
Biophysical Chemistry by Cantor & Schimmel.
 
Assignments:
Reading and problems assignments are either from Quantum Chemistry & Spectroscopy [QCS] or from Thermodynamics, Statistical Thermodynamics, and Kinetics [TSK]
Date Reading Problems Q&A
04/16 TSK Read Ch.13 to the end. Also: Ch.15.4 (entropy) Do Ex.Prs: 13.3-13.5. Qs: 13.6,9-11. Prs: 13.9,10,13-14,22-24. Perform the assessment, from the previous HW assignment, of the accuracy of the Stirling's formula.    
04/14 Reading and problems from TSK (see also Files on ELMS): Ch.13: 13.1-13.5, [Ch.12 -- refresher on probabilities]. Qs: 13.1-5; Pr: 13.1,6,7,12,,27. Using your calculator find the smallest value of n for which the Stirling's formula (see lecture slides, Equation 1) approximates the value of n! within 10% accuracy, 1% accuracy. Do the same for ln(n!) (see Equation 2 in lecture slides on ELMS and also Ch. 12.3). For the latter, you might need Matlab or a similar program to assess the 1% accuracy level.    
04/09 Ch.10.1,10.2,10.3 & 6.2, (+ME 9) Ch.10: Qs: 10.1, 10.7. Prs: 10.2, 10.3, 10.7, 10.12, 10.13. Your graded Homework #3 (due by 12:00 pm on Friday April 17) is here.  
04/07 Ch.9 to the end; Ch. 10.1, and ME9 Ch.9: Ex.Pr: 9.4-9.6; Qs: 9.12,9.19; Pr: 9.15,9.23-25. Calculate the average value of the potential energy of electron in the H atom in the 2s state and compare your result with the total energy of the electron. Does the relationship < V > = 2E that we obtained in class today for 1s electron hold for these states too? Calculate the average distance, < r >, from the nucleus for 1s electron, and compare 1/< r > with < 1/r >. My answers/solutions to Exam #1 problems are posted below under Exam #1 Solutions and Statistics.  
04/02 Ch.9: 9.2-9.3-9.4 Ch.9: Ex.Pr: 9.1-9.3; Qs: 9.5,9.6,9.10,9.15,9.18. Do the HW assignments from the previous lecture. Calculate and compare the energies of electrostatic interaction and gravitational interaction between electron and proton. What is the degeneracy of the state(s) of H atom with the principal Q.N. n? For 2s and for 2pz orbitals determine the points in the 3-D space where there is the highest probability to find the electron.
03/31 Ch.9: 9.1-9.2 Ch.9: Qs: 9.8. Pr: 9.2. Show by direct substitution into the equation for the radial part of the wave function (Eq. 9.5 in the textbook) that R(r) = A*exp(-r/a) is a solution to Shroedinger Equation for H-atom when l = 0; determine the values of a and E. Calculate and compare the energies of the electrostatic interaction and the gravitational interaction between electron and proton.    
03/26 Ch.7: 7.6, 7.8. Ch.7: Qs: 7.2-4,7.12,7.13; Pr: 7.28,7.31-32, 7.35-38. Prove that the operator of the square of the angular momentum, l^2 = lx^2+ly^2+lz^2, commutes with lx and ly and lz. For this you might want to use the commutators of lx, ly and lz -- see your lecture notes or Equations (7.63) from the textbook. Also, by performing the integration as we did in class, verify that the normalization coefficients for rank-2 (l = 2) spherical harmonics in Equations (7.65) in the textbook are correct (do it for a couple of harmonics). A video recording and accompanying handwritten notes from a similar lecture given in 2021 are available on ELMS under Files -- look for filenames that contain "L13_2021".  
03/24 Ch.7: 7.5, 7.7 Ch.7: Qs: 7.9, 7.11; Pr: 7.31, 7.32, 7.33, 7.36.  
03/12 Midterm Exam #1 Bring your calculator.    
03/10 Prepare for the midterm exam. After the exam: Ch.6: 6.1,6.3,6.4 Ch.6: Example Prs: 6.1, 6.3-6.5. Qs: 6.5,6.8,6.13,i6.14,6.18. Pr: 6.1,6.3,6.6,6.7,6.13,6.20. Prove the genearal relationships for the commutators which I gave you in class. Specifically, evaluate the commutator [A,BC]. Answers/solutions to HW #2 problems are here.  
03/05 Ch 7: 7.2, 7.4, Math Essential 7 & 8 Ch.7: Ex.Pr.: 7.4,7.5. Qs: 7.10,7.19. Pr: 7.25,7.27, 7.32(b). Tentative equations sheet for the upcoming Exam #1 is here
Review session for the upcoming midterm exam #1 will be held via zoom on Tuesday March 10 at 7 pm. Bring your questions!
Example problems from the previous year Exam #1 are here. Answers/solutions to these problems are here. Please look at them only after you solved or attempted to solve the problems yourself.  
03/03 Ch 7: 7.1,7.3 Ch.7: Qs: 7.1,7.5,7.7; Ex.Pr: 7.2,7.3; Pr: 7.2,7.7,7.9,7.10,7.14,7.16. Your graded Homework #2 (due on March 10) is here Answers/solutions to graded Homework #1 are here  
02/26 Ch.5: 5.1-5.2, 5.5-5.6,(5.7) Ch.5: Qs: 5.6,5.8,5.13,5.14; Pr: 5.3. Harry Potter and the Platform 9 3/4: Using the "gravitational wall" model discussed in class calculate the penetration length for (1) a proton and (2) an electron. Assume velocity v = 2 m/s; wall height H = 2m. And don't forget to submit your graded HW#1.  
02/24 Ch.4: 4.3; Ch.5: 5.3 Ch.4: Pr: 4.19-21, 4.23, 4.24, 4.27; Ch.5: Pr: 5.1, 5.2.  
02/19 Ch.4: 4.2 & 4.4, also 2.1 Ch.4: Ex.Pr.4.1-4.4; Qs: 4.9,11,14,15,18,19. Prs: 4.14,4.15,4.16,4.30,4.34,4.35.
Harry Potter and the Basilisk Problem. Assume the Basilisk in the corridor is in the state described by the wavefunction of 1D PIB corresponding to n = 3. Suggest a strategy that would allow H.P. to get trough the corridor (from one end to another) without being bitten by the beast.
Your Graded HW #1 (due on Feb 27) is here.
 
02/17 Ch.4: 4.2 (& 4.1) Ch.4: Prs: 4.7, 4.8, 4.11, 4.13. Some useful trigonometric identities and other formulae can be found here and on ELMS.  
02/12 Ch.4: 4.1. Ch.4: Qs: 4.4,4.5; Pr: 4.1-3. Also do previously assigned end-of-chapter problems. Video recording of a similar lecture (it was Lecture 5) from 2021 was posted on ELMS together with the lecture notes.  
02/10 Ch.3: to the end + Ch.2: 2.2,2.5,2.6. Ch.3: Qs: 3.10-12; Prs: 3.11,3.13,3.21. Finish doing end-of-chapter problems from the previous assignments.  
02/05 Ch.3: to the end + Ch.2: 2.5,2.6. Ch.3: Qs: 3.4,3.5,3.6-8; Pr: 3.1,3.2,3.9,3.12,3.19,3.20,3.22.
A Schroedinger's cat problem: When opening the box, Schroedinger's cat was found alive in 64% of experiments and dead in 36%. Based on these observations, reconstruct the wavefunction of the cat in the box.
 
02/03 Ch.3: 3.1-3.3; Ch.2: 2.4, [2.5 -- prep. for next lecture]. Refresh your knowledge of complex numbers (ME 6). Ch.2: Pr: 2.13,2.14,2.17,2.19,2.20; Ch.3: Qs: 3.1,3.2  
01/29 Snowday. QCS: Ch.1 & ME 6 Ch.1: Do Example problem 1.3 from Ch.1: determine the radius of the lowest-energy orbit of electron in Bohr's planetary model of the hydrogen atom. Do Numeric Problem 1.15.
Using Wien's displacement law, λmax*T=1.44/5 cm*K, perform the following calculations: (1) estimate λmax for your body radiation, and (2) assuming that the maximum amount of Sun's radiation is in the yellow range, i.e. λmax ~ 580 nm, estimate the temperature of the Sun's surface.
It's not too late to prepare yourself for the course. The relevant information can be found below and also on ELMS. 
 
01/27 Snowday. Watch video recording and lecture notes of lecture # 1 from year 2021 posted on ELMS under Files.    
before 01/27 Prepare yourself for the course. The relevant information can be found here.  Pepare yourself for the course. The relevant information can be found here.   
Exam # 1: Exam # 2: Final Exam:
Statistics Statistics Statistics
Solutions Solutions Solutions
     

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