Exam #2 – Electrons, Compounds, and Structure

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Chemistry 161
Exam 1, April 26th, 2010
Name: ____________________
Show all work for full credit
Exam #1 – Conversions, the Atom, and Electrons
SHOW ALL OF YOUR WORK TO RECEIVE
FULL CREDIT
Make a note of the point value of each question, and allocate your time accordingly.
Carefully read each question.
Where appropriate, work must be shown to receive proper credit.
Take your time, make sure to check your work for mistakes when you are finished.
Credit for all calculations includes use of units, correct number of significant digits
Partial credit will be awarded based on work shown.
If you get stuck, move on to another problem.
Use a pencil so that you can erase any mistakes.
Page
Points
2
30
3
24
4
18
5
28
TOTAL
100
Score
1/5
Chemistry 161
Name: ____________________
th
Exam 1, April 26 , 2010
Show all work for full credit
1. (12) A car's gas mileage is reported as 1.706 x 105 chains per hogshead.
What is this in miles per gallon?
Write your answer with the proper number of significant digits.
Possible useful relationships:
1 chain = 792 inches (exact)
1 mile = 80 chains (exact)
1 hogshead = 238.5 liters
12 inches = 1 foot (exact)
1 liter = 0.264 gallons
1 mile = 5280 feet (exact)
2. (6) Convert 4.2 m3 to mm3.
3. (6) A particular metal block has a density of 4.21 g/ml. The block weighs 1.1 kg. What is the
volume of the block in cm3?
4. (6) Write the complete ground state electron configuration for silver (Ag). Do not use cores to
abbreviate your answer.
2/5
Chemistry 161
Name: ____________________
th
Exam 1, April 26 , 2010
Show all work for full credit
5. (10) Draw an energy level diagram representing the ground state electron configuration for the ion
Fe2+. (Hint: be mindful of which electrons come off first for transition metals)
6. (6) Circle and clearly label the electrons with the following quantum numbers in your diagram
above.
a.
3, 1, 0, +½
b.
2, 1, 1, -½
c.
2, 0, 0, -½
7. (3) How many valence electrons do the following atoms have:
a. S
b. Ag (hint: refer to question 4)
c. C
8. (5) How much does 1 average atom of lead weigh, in grams?
3/5
Chemistry 161
Name: ____________________
th
Exam 1, April 26 , 2010
Show all work for full credit
9. (8) Fill out the following table with the quantum numbers for all of the electrons in a neutral
sodium atom (you may not need every blank, or you may need additional blank spots as necessary):
n
l
ml
ms
10. (6) Circle the appropriate atom or ion that
a) has the highest ionization energy
Zr
Re
Ga
Hf
b) is the most metallic
Pb
W
Si
Fe
c) has the largest atomic radius
As
Ga
B
Al
11. (4) How and why does atomic size change across a period on the periodic table (left to right)?
4/5
Chemistry 161
Name: ____________________
th
Exam 1, April 26 , 2010
Show all work for full credit
12. (6) Draw the electron cloud, or shape, that represents the following orbitals (relative size counts):
1s
3p
2p
13a. (10) Calculate the energy change (in Joules) and wavelength of light emitted (in nm) for a
hydrogen atom electron transition from n = 7 to n = 1.
 1
1 


2
2  J
n
n
i 
 f
ΔE = -2.179 x 10-18 
h = 6.626 x 10-34 J•s
13b. (1) Is the photon emitted in question 13a visible to the human eye?
13c. (1) Is the photon emitted in question 13a a part of the Balmer series?
14. (10) How many Joules of energy are there in Avogadro's number of violet (or blue) photons.
h = 6.626 x 10-34 J•s
5/5
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