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SCH4U
READINGS & QUESTIONS ON ATOMIC STRUCTURE
texts used: B&H = Brady & Holum, Fundamentals of Chemistry (green handout)
N = Nelson, Chemistry 12 (our textbook)
I. Early Models: (optional reading N: p. 162-166),
1.What new information was incorporated into the model of the atom as a result of the early cathode ray tube
experiments?
2. Consider Rutherford’s Gold Foil experiment.
a) Using the analogy of a shooting range with a gun, bullet, and paper target, what does each item represent
in the experiment? (see N:p. 163-4)
b) Using the shooting range analogy, why were the results so startling?
3. How did Rutherford infer that the nucleus was:
a) very small (compared to the size of the atom)
b) positively charged
4. What was the main criticism of Rutherford’s model by Classical Physicists?
II. Quantum Theory (optional reading N: p. 169-172)
5. How are the terms "quantum" and "photon" related?
6. Planck related the energy of a photon to the frequency of light with his equation: E = hf
Explain why red light (f=1014 Hz
) may not cause ionization of an atom whereas, ultraviolet light (f=10 16 Hz) does.
III. The Bohr Model of the Atom & Spectra N: Read p. 174-179:
7. Describe the electron in an atom as Bohr understood it.
In the equation:
E = -R/n2
a)What does E represent?
b) What does n represent? describe any restrictions on the value of n
c) Why is the negative sign present?
8. What is meant by the term “ground state”
9. When creating his new atomic theory, Bohr used on important new idea (theoryP and primarily one important
experimental area of study. Identify each.
10. State two differences between Excitation and Relaxation
11. What is the empirical (observed) distinction between emission and absorption spectra?
12. In General terms, how did Bohr explain emission and absorption spectra?
13. If there are many relaxation transitions possible in the Hydrogen atom, why are only 4 bright lines observed on the
atomic spectrum?
14. What transition involves absorbing the most energy? a) E6→E1
b) E1→E2
c) E3→E4
15. What are three things that Spectra can be used for?
16. Why is spectroscopy so useful to Astronomers?
17. Compare atomic spectra to the continuous spectrum of light.
18. Why are atomic spectra compared to fingerprints?
19. Explain what is meant by the phrase “the energy of electrons in atoms in quantized”.
20. What successes did Bohr’s model of the atom have?
21. What failures did Bohr’s model have?
IV. “The wave nature of matter” B &H: Read 6.4, p. 196-197
22. Why were Bohr’s efforts doomed to start with?
23. Write De Broglie’s mathematical description of “matter waves” and explain what the terms represent.
24. Why do objects in the macroscopic everyday world not appear to exhibit any wave-like properties?
25. What are diffraction patterns and what causes them?
26. Are diffraction patterns a phenomenon of waves or a phenomenon of particles?
27. optional: using the three equations: Planck's E = hf, Einstein's E = m c2 , and the universal wave equation: v=f 
derive De Broglie's equation:  = h/mv (remember that c is the speed of light)
V. “Electron Waves in Atoms” B & H: section 6.5-6.6 ( Read p. 199-203)
28.
29.
30.
31.
32.
33.
34.
Why is the current theory of electron structure sometimes called “Wave mechanics”?
Why is the current theory of electron structure sometimes called “Quantum mechanics?”
Distinguish between travelling waves and standing waves
What are nodes?a) in a guitar string
b) in an electron wave
For a typical standing wave (eg. guitar string) what restrictions are placed on wavelength ()?
Electron waves are compared with which type of wave (standing or travelling)?
What are “orbitals”?
VI. Quantum Mechanical Model: class note
35. State Heisenberg’s Principle as a mathematical statement or in words.
36. In Schrodinger’s Wave equation what does Ψ represent?
37. Plotting Ψ2 in three dimensions shows what information?
38. How is Bohr’s idea of fixed Energy levels retained in Schrodinger’s Wave equation?
38. An unspoiled and peaceful tribe was discovered deep within the Amazon jungle, isolated from the rest of the world.
National Geographic went on location to do a film documentary of this fascinating culture and within 20 years much of the
traditional practices were abandoned. Which of the general principles or rules related to atomic theory does this story
illustrate? Explain.
VII. “Quantum Numbers”
B & H: section 6.5-6.6 ( Read p. 199-203)
39. What is the principal quantum number used for? What variable is used to describe it?
40. Using the comparison to a staircase, are the “energy levels” in an atom equal or unequal “steps”? Explain.
41. How many subshells are in the third shell? What is the relationship between subshells and energy levels?
42.. What else does the secondary quantum number describe?
43. What is the relationship between the secondary quantum number and the magnetic quantum number? Provide
an example using l=3 to illustrate your point.
44. Complete the following chart:
Principal Quantum
Number, n
Secondary Quantum
Number, l
1
Magnetic Quantum
Number, m
Spin quantum number, ms
0
+1/2, -1/2
l
0
1
-1, 0, +1
3
VIII. Read B & H p. 203-204: “Electron Spin
45.
46.
47.
48.
How is electron spin described?
What is the symbol used for the quantum number for electron spin and what values are allowed?
State Pauli Exclusion principle in two different ways:
How is the “spinning top” analogy is used to explain this quantum number
IX. Atomic Structure and the Periodic Table: Read N p. 185-191
49.
Compare and contrast orbits and orbitals using a chart.
Orbits
Orbitals
50. Complete the following table:
0
value of l
letter designation
1
2
3
51. Distinguish between a shell and a subshell, specifically referring to the quantum numbers which represent
them.Use the diagram to the right to answer the next four questions.
52. Which subshell within the shell n=3 has the highest
energy? Which orbital(s) in the M shell has/have the
lowest energy?
53. In General, how does the energy of an electron relate to
the principal quantum number? (i.e., n=1, 2, 3…)
54. What do you notice about the energy of the 3d orbitals in
comparison to the 4s orbitals? How does this conflict with
your answer for (b)?
55. How would the energy level diagram for Hydrogen appear
differently than the one shown to the right?
56. If each orbital can house 2 electrons (one with +1/2 spin, one
with -1/2 spin), how many electrons can be held:
i. in the first shell? (n=1)
ii. in the second shell? (n=2)
iii. in the third shell? (n=3)
iv. in the fourth shell (n=4)
57. Within the fourth shell (n=4), list the subshells in order of least
to greatest energy.
58. When placing arrows inside the same orbital in an energy
level diagram, how must they be oriented? What does this
represent?
59. Complete the following chart:
Sublevel Symbol
Number of orbitals
within that sublevel
s
p
d
f
3
60. What is the Aufbau principle?
61. What is Hund’s Rule?
62. How do you use the following aufbau diagram to determine electron configuration? Ultimately, what decides the
number of electrons placed in a neutral atom?
63. How would energy level diagrams change if you were dealing with anions?
64. For cations, which electrons do you remove from the energy diagram?
65. State what “block” of the periodic table (eg. “s-block”, “p-block”) you find each of the following:
a) halogens
b) transition metals
c) lanthanides
d) alkali metals
66. What is the subshell designation (eg. 1s) corresponding to the following values of n and l?
i. n=2, l = 1 (ans. 2p)
ii. n=3, l = 2
iii. n=1, l = 0
iv. n=4, l = 3
v. n=2, l = 0
vi. n=3, l = 1
67. Which of the following sets of quantum numbers are unacceptable?
i. n = 2, l = 1, m = -1
v. n = 1, l = 1, m = 0
ii. n = 3, l = 0, m = 0
vi. n = 3, l = 3, m = -1
iii. n = 4, l = 3, m = 3
vii. n = 1, l = 0, m = -1
iv. n = 2, l = 3, m = -1
viii. n = 1, l = 0, m = 0
l
l
l
l
l
l
l
l
68. What subshells are found in the second shell? Fifth shell?
69. What subshells are found in the N shell? K shell? L shell?
70. Which subshell is higher in energy for any multi-electron atom?
i. 2s or 3s
v. 3d or 4p
ii. 4p or 4d
vi. 4d or 3d
iii. 4s or 3d
vii. 5f or 6s
iv. 3p or 4p
viii. 5d or 6s
71. How many electrons can occupy:
i. 3s subshell
ii. 4p subshell
iii. M shell
iv. the shell with n=4
v. the subshell with n=4 and l = 3
vi. the K shell
vii. the 4f orbital
viii. the subshell with n = 3 and l = 2
72. Draw energy level diagrams for:
i. calcium atom
ii. phosphorus
iii. manganese
iv. nitride ion
v. bromide ion
vi. cadmium ion
vii. potassium ion
viii. chloride ion
X: Explaining Using Electronic Configurations N p. 192-196
73. Write full electronic configurations for: a) Sc, b) Kr
74. Write condensed electronic configurations for: a) 41Nb b) 73Ta c) 53 I
Nelson text: p. 194, #6,8, 9
p. 197, #9, 10, 11, 12, 13
_________________________________________________________________________________________________
ATOMIC STRUCTURE AND MOLECULAR
 Identify various orbitals up to n =3: s, p, d, and
ARCHITECTURE
be able to distinguish between 1s, 2s and 3s, for
TEST REVIEW SHEET-2014
example, or between 3dxz and 3dz2, nodes
 identify number of orbitals and subshells in each
ATOMIC STRUCTURE TEST TOPICS:
shell, number of nodes in each orbital.
 Provided with the test: periodic table with elements
 Successes/failures of Quantum Mechanical
& atomic numbers
model
1. Early Atomic models: Dalton’s, J.J. Thomson’s,
Rutherford’s gold foil experiment and Nuclear model,
problems with Rutherford’s model
2. Planck's Quantum Theory
2. Bohr's Model, main points, successes, failures,
Spectroscopy, Atomic spectra (emission, absorption),
advantages of atomic spectra, ground state, excited state,
relaxation, stationary states, E=-R/n2 , quantized energy
levels (you will NOT have to do BOHR calculations of
spectra wavelength on the test)
3. Quantum Mechanical Model
 Wave-particle dual nature of the electron
 De Broglie and Matter waves λ = h/mv
 Heisenberg Uncertainty principle
 Schrodinger Wave Equation, Wave functions,
Orbitals as probability plots, nodes, Quantum
numbers, Shells, subshells etc.
4. Energy level diagrams for atoms, cations and anions
(Hunds rule, Aufbau Principle, Pauli Exclusion principle ...)
 electronic configurations (both expanded and
condensed) and how the subshells correspond to
the periodic table, valence shells
 Anomolous Configurations eg. Au
 Paramagnetic vs. diamagnetic elements,
ferromagnetism
 Explaining Some multi-valent transition metals
eg. Pb2+ and Pb4+
Some review questions can be found in the textbook:
pg 219 Self Quiz #1-8,10-12, 14-19, #12-19, pg. 220
Review #1-3,6,10,12-17