Exam 1
Name
Directions: Show all work. Significant figures matter! Units matter!
9/22/15
1. Which of the following sets of quantum numbers are forbidden? Select all that apply. (3)
a.) 2,1,1, -½
b.) 3,0,1, ½
d.) 6,0,0, ½
e.) 4,3,-3, -½
c.) 3,3,0, -½
2. Which of the following sets of derived units can not be used to represent volume? (3)
a.) ft3
b.) L
d.) mm3
e.) kg3
c.) µL
3. Data from a certain experiment is easily reproduced. The percent error is found to be higher
than 20%. The experiment is: (3)
a.) Precise
b.) Accurate
c.) Precise and Accurate
d.) Neither
4.
207
82𝑃𝑏
isotopes undergo radioactive decay to produce 203
80𝐻𝑔 isotopes. This represents: (3)
a.) Alpha Decay
b.) Beta Decay
d.) Fusion
e.) Fission
c.) Gamma Decay
5. It is determined that Photon A has a shorter wavelength than Photon B. Select all true
statements. (3)
a.) Photon A has less energy than B
b.) Photon A has a lower frequency than B
c.) Photon A has a higher frequency than B
d.) Photon A has more energy than B
6. In terms of chemical reactivity, calcium is most similar to: (3)
a.) K
b.) Sc
d.) H
e.) Na
c.) Ra
7. Which of the following species would you expect to be the smallest? (3)
a.) He
b.) Au3+
d.) Hg
e.) W6+
c.) S2-
8. A certain isotope ion has 36 electrons, 45 neutrons, and a net charge of 2-. Write the isotope
symbol. (6)
9. Balance: Ammonium perchlorate(s)  Chlorine(g) + Oxygen(g) + Nitrogen(g) + Water(L) (5)
10. How was the Bohr model developed? What is its limitation? (5)
11. Fill in the table below. (6)
Name
Molecule
N2O4
Hydrobromic acid
Nb2(C2O4)5
Aluminum sulfide
12 Write the noble gas electron configurations for Mo and Mo+ (5)
13. Consider the table of ionization energies below for an unknown, in attojoules (aJ). Based on
the values shown, how many valence electrons would you expect this element to have? Why? (5)
Ionization I1
IE (aJ)
0.53
I2
0.98
I3
1.99
I4
3.47
I5
11.05
I6
12.88
I7
15.01
I8
18.79
14. Solid beryllium is added to an aqueous solution of yttrium (III) cyanide. A single replacement
reaction occurs. Write out the full reaction. Then, write the re-dox reactions and label the oxidizing
and reducing agents. Use the back of this page. (12)
15. Research grade propanol (C3H7OH) costs $90.53 per kilogram. You purchase a 1.6 gallon bottle
from a chemical supplier at a cost of $436.20. What is the density of propanol in units of mg/cm3?
(10)
16. A green laser pointer emits photons having a wavelength of 510 nm. The laser operates at
5mW of power. Calculate the number of emitted photons per minute. (10)
17. A photon having a wavelength of 83nm strikes the surface of a sheet of vanadium, resulting in
the ejection of an electron. Given that the threshold frequency of vanadium is 7.674 x 1014 s-1,
calculate the velocity of the ejected electron in units of km/hr. (15)
Equations
En = nhν
νλ = c
ρ = mass/volume
Ekinetic = Ephoton − Ethreshold = hνp − hνT
For an electon in motion: 𝐸𝑘𝑖𝑛𝑒𝑡𝑖𝑐 =
𝑚𝑉 2
2
h = 6.626 x 10-34 Js
c = 3 x 108 ms-1
m = 9.109 x 10-31 kg
power: W = J/s
1 gallon = 3.7854 L
BONUS
How was the electron discovered? (3)
What conclusions about chemical reactivity can be made based on atomic periodicity? (4)
Explain the role of the neutron in the nucleus of an atom. (3)