| Never enter units in your answers. Be
sure to use the units indicated on the HW submission page.
Enter numbers without commas. 23,546 should be 23546 Always enter a * for multiplication. g(H+h) should be g*(H+h). |
| You are now obtaining input data for CID = |
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Submitted Answers will be graded M
12/1, T 12/2, W 12/3, Th 12/4, and F 12/5 at 12:00 noon.
| Problem 11.1 | |||||||||||
| What you should learn: The first three questions are again reading questions. | |||||||||||
| Problem: Did you read Chapter 41 Sections 1-3? Type Y or N in the box. | |||||||||||
Results of previous submissions:
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| Problem 11.2 | |||||||||||
| What you should learn: Reading... | |||||||||||
| Problem: Did you read Chapter 42 Sections 1-3,6-7? Type Y or N in the box. | |||||||||||
Results of previous submissions:
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| Submit HW answers. | |||||||||||
| Problem 11.3 | |||||||||||
| What you should learn: Reading... | |||||||||||
| Problem: Did you read Chapter 43 Sections 1,5,6? Type Y or N in the box. | |||||||||||
Results of previous submissions:
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| Submit HW answers. | |||||||||||
| Problem 11.4 | |||||||||
| What you should learn: The wave functions for the infinite square well resemble the standing waves on a string. | |||||||||
| Problem: For an infinite square well potential, the n = 3 the wave function (the one with the third lowest energy; that is, two states have lower energy) has how many spots where there is no probability of finding the wave? | |||||||||
Results of previous submissions:
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| Problem 11.5 | |||||||||||
| What you should learn: The wave function provides us with information on the probability of finding a system in a given state. For spatial wave functions in one dimension, the probability density (probability per unit length, in one dimension) of finding a particle in a region is P(x) = ψ*(x) ψ(x). | |||||||||||
| Problem: A particle in an infinite square well potential has a wave function given by ψ(x) = A sin(kx). What is the probability of finding the particle between x = 0 and x = b (b is given below)? | |||||||||||
| Constants and fixed variables:
A = 1414 m–1/2 k = 9.42 x 106 m–1 |
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Variables that must be changed with each
submission:
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| Hints:
How do I do the integral? |
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Results of previous submissions:
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Answer range:
Probability = 4.93 to 33.3 % Submit HW answers. |
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| Problem 11.6 | |||||||||||
| What you should learn: The Schrodinger equation is constructed by adding the kinetic and potential energy operators. The kinetic energy operator, in turn, is constructed from the momentum operator. This is a simple exercise in using the momentum operator. | |||||||||||
| Problem: The wave function for a particle with definite momentum (a plane wave) is given by the formula ψ(x) = Aeikx. Use the momentum operator, p = –iħ ∂ /∂x, to find a numerical value for the particle's momentum. | |||||||||||
| Constants and fixed variables:
hbar = 6.582 x 10–22 MeV s |
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Variables that must be changed with each
submission:
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| Hints:
Recall that the wave function represents a state of definite momentum, and if p is the momentum operator and p is the value of the momentum, pψ = pψ I need help with the units |
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Results of previous submissions:
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Answer range:
p = 100 to 300 MeV/c Submit HW answers. |
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| Problem 11.7 | |||||||||||
| What you should learn: The Bohr model of the atom correctly predicts energy levels of the hydrogen atom. The frequency of emission spectra can be determined by considering the change in electron energy in transitions between energy levels. | |||||||||||
| Problem: Find the wavelength of light given off when a hydrogen electron undergoes a transition from the ni = 8 energy level to the nf energy level listed below. | |||||||||||
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Constants and fixed variables:
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Variables that must be changed with each
submission:
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| Hints:
The hydrogen energy levels are En = E1/n2. Then use E = hf and c = λf. |
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Results of previous submissions:
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Answer range:
lambda = 90.0 to 1950 nm Submit HW answers. |
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| Problem 11.8 | |||||||||
| What you should learn: You should be familiar with the basic characteristics of the Bohr model. | |||||||||
| Problem: Which of the following
are not true concerning the Bohr model of the hydrogen atom?
A. The Bohr model gives the correct energies for the hydrogen atom. B. The Bohr model is based on quantization of angular momentum. C. Bohr's quantization equation for angular momentum proved to be incorrect. D. The radius of the nth Bohr orbit is n times the radius of the smallest orbit. E. The Bohr model correctly predicts the shape of p orbitals. Express your answer as a sum. If A, B, and C are correct, enter A+B+C |
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Results of previous submissions:
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Answer range:
Submit HW answers. |
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| Problem 11.9 | |||||||||
| What you should learn: The next few problems relate to quantum numbers for the hydrogen atom. | |||||||||
| Problem: Which of the following
statements are true?
A. The possible values for the principle quantum number (n) are 0,1,2,3,... B. When n = 4, the possible values of ℓ are 0,1,2,3,4 C. When ℓ = 4, the possible values of mℓ are –4,–3,–2,–1,0,1,2,3,4 Express your answer as a sum. If A, B, and C are correct, enter A+B+C |
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Results of previous submissions:
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| Problem 11.10 | |||||||||||
| What you should learn: More on quantum numbers for the hydrogen atom... | |||||||||||
| Problem: If the angular momentum quantum number has the value listed below, what is the value of the electron's orbital angular momentum? | |||||||||||
| Constants and fixed variables:
Planck's constant: h = 4.136 x 10–15 eV s |
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Variables that must be changed with each
submission:
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Results of previous submissions:
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Answer range: L = 2.20 x 10–15 to
5.60 x 10–13 eV s
Submit HW answers. |
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| Problem 11.11 | |||||||||||
| What you should learn: More on quantum numbers for the hydrogen atom... | |||||||||||
| Problem: For the same value of ℓ given in the previous problem, find the largest possible value of the z component of the angular momentum. | |||||||||||
| Constants and fixed variables:
Planck's constant: h = 4.136 x 10–15 eV s |
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Variables that must be changed with each
submission:
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Results of previous submissions:
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Answer range:
L = 1.95 x 10–15 to
5.60 x 10–15 eV s
Submit HW answers. |
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| Problem 11.12 | |||||||||
| What you should learn: The next problems relate to types of molecular bonds. | |||||||||
| Problem: Which type of bond is created when one type of atom in a solid loses an electron and another type of atom gains that electron?
A. ionic B. covalent C. van der Waals D. hydrogen Note that you will only be allowed two submissions on this problem and the following multiple choice problems. |
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Results of previous submissions:
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| Problem 11.13 | |||||||||
| What you should learn: More on molecular bonds... | |||||||||
| Problem: Which type of bond is
created when covalent bonds leave "bare" protons exposed on a molecule?
A. ionic B. covalent C. van der Waals D. hydrogen |
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Results of previous submissions:
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| Submit HW answers. | |||||||||
| Problem 11.14 | |||||||||
| What you should learn: A last question on molecular bonds... | |||||||||
| Problem: In covalent bonds, the
electron wave function is fairly large between the nuclei of atoms. This
leads to
A. a smaller probability of finding electrons between the positive charges, thereby creating a bond by enhancing the exterior electron cloud B. a larger probability of finding electrons between the positive charges, leading to an attractive positive-negative-positive "sandwich" C. an enhanced probability of radial extension, leading to a shared electron that results in binding D. a combination of all of the above |
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Results of previous submissions:
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Answer range:
Submit HW answers. |
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| Problem 11.15 | |||||||||
| What you should learn: The last problem relates to band structure in solids. | |||||||||
| Problem: In which type of solid
is there a filled valence band and an empty conduction band with a large
band gap in between?
A. a superconductor B. a conductor C. a semiconductor D. an insulator |
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Results of previous submissions:
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Answer range:
Submit HW answers. |
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