PRACTICE EXAM III
CHEM 161-01&03
Dr. Overway
November 2009
Instructions: Do not open this test booklet until you are instructed to do so.
Show your work in order to receive partial credit. Keep track of units and use the correct significant
figures. The following information may be useful during the exam.
E
c=
% Error 
Speed of light (c) = 2.9979×108 m/s
observed - true
 100%
true
Planck’s constant (h) = 6.626×10-34 J·s
Avogadro’s number = 6.022×1023 things/mole
hc

 hν
CHEM 161-01&03
PRACTICE EXAM III
1. An electron in a hydrogen atom starts from some unknown energy level and jumps to the n = 8 state
when it absorbs a photon with an energy of 2.08210-19 J. This electron started from what energy
level (give the n-value)? Round your answer to the nearest whole number.
Skip this problem
2. Rank the following regions of the electromagnetic spectrum in order of wavelength, from the
shortest wavelength to the longest wavelength: visible, infrared, x-rays, ultra-violet, radio waves
3. The Photoelectric Effect changed the view of how scientists view matter. Explain this and give a
real-world example.
4. Circle each of the following quantum number combinations that are possible (which could exist)?
A) (2,2,-3,½)
B) (3,1,0,-½)
C) (3,2,3,½)
5. Draw an example of each of the following orbital shapes:
A) a d orbital
B) an s orbital
C) a p orbital
D) (2,1,1,¾)
6. Provide four the quantum numbers for the following (use the format (n,l,ml,ms) ):
A) the last electron to fill the last orbital of phosphorus: (
,
,
,
B) the electron that is removed when Calcium ionizes (Ca  Ca+ ): (
)
,
,
,
)
7. Provide the electron configuration for the following species.
A) Al (w/o noble gas shorthand)
.
C) Zn (using noble gas shorthand)
.
8. Given an example of a transition metal that is an exception to the electron configuration rules
(provide the electron configuration). Explain why this happens.
9. Give the electron configuration of Na+ and O2- . What is the term for these similar electron
configurations?
10. Given the following electron configurations for Ca:
1s22s22p63s23p64s14p1
1s22s22p63s23p64s2
1s22s22p63s23p64s13d1
identify the with is the ground state (GS) and excited state (ES) configurations
11. True/False
Metals are easier to ionize than non-metals
The (n-1)d electrons are ionized before the (n)s electrons.
As the principle quantum number (n) increases, the ionization energy of an atom decreases.
As the principle quantum number (n) increases, the size of an atom increases.
A Lewis structure describes in detail the 3-dimensional shape of a molecule.
As you move down a column of the periodic table, you observe that the size of the atom
decreases.
As you move across the periodic table (from left to right), you observe that it takes more energy
to ionize the atom.
12. Why is the first ionization energy of oxygen less that the ionization energy for nitrogen when the
general trend shows increasing ionization energy as you go from left to right on the Periodic table?
13. Explain why ionization energies, in general, increase as you move across (from left to right) the
periodic table.
14. For the molecule SO3F - (note the negative charge),
A) Draw and circle the most stable Lewis structure (s) and any resonance structures
B) Account for the electrons in the molecule using the box to the right
E) Calculate the formal charges of the most stable structure
H = ____
N = ____
S = ____
B = ____
Most stable structure
FCS = ____
FCO = ____
FCO = ____
FCO = ____
FCF = ____
15. What force holds two atoms together? What subatomic particle is the principle actor in these bonds?
16. Describe the difference between ionic, covalent, and polar bonds. Give an example of each.
17. Rank the polarity (or electronegativity difference) of the following bonds from least polar to the
most polar.
H-Br , H-F , H-Cl , H-I
_____ < _____ < _____ < _____
18. Rank the order of the following bonds from weakest to strongest
C-I, C-Cl, C-F, C-Br
_____ < _____ < _____ < _____
19. Rank the order of the following bonds from least polar to most polar
C-N, C-C, C-F, C-O
_____ < _____ < _____ < _____
20. Determine the frequency of a photon from a green laser (532 nm).