Midterm is worth 68 points, not including extra credit, which gives you up to 9 extra points.
For multiple choice- please circle the letter and fill in completely. If you don’t do this there will be grade
consequences!!!!
1. A B C D E F
RIGHT NOW- fill in your ID number, the bubbles and your version letter on the answer sheet, do this now so you don’t forget.
There are four versions of the exam. The difference in the multiple choice is the rearrangement of letters, and the short answers are designed to look similar. If you copy, you are most likely copying the
wrong answer, this makes cheating even more pointless than normal, please don’t do it.
If you think someone nearby may be copying, or something is simply disturbing you, please let me know and we can adjust people’s seats appropriately. Tell me as early as possible.
Be sure to sign the sign in sheet. This is my record that you attended the class. If you are not sitting in your assigned seat for a reason approved by me, you’ll need to make sure to write the seat where you are actually sitting next to your name.
You will also need to show your ID to the TA when you turn in your exam.
. You may (and should) keep the exam sheet. Go home, retake it, see how you did  . If you write any work on scrap paper, the question sheet or anywhere other than the space given, it will not be graded and you will not get any credit for it. Do not write on the back of the sheets, do not write anything you want graded anywhere other than the space given. I’d suggest writing in pencil or doing scratch work elsewhere and then copying over.
I think it’s a fairly long exam. Pace yourself, pay attention to point distribution and do your best to complete it all.
Exams will be sent through eee dropbox. They will be graded the same day as you take it, and the grades will be posted at least by the next morning, if not sooner. It will take a week or more to get the exams back to you depending on how backed up the system is. I can’t make this go faster, it is completely out of my hands.
. At that point there is nothing that being stressed will do for you. So take a deep breath, pick up your writing utensil and show me how

1. Name SnO:
A. Tin II oxide
B. Stannous Oxide
C. Stannic oxide
D. Tin IV oxide
E. A and B
F. A and C
G. C and D
2. What is the correct name for the following empirical formula CH
3
COONa?
sodium acetate
3. A compound is made up of 46.7 % Nitrogen , 39.9%
Carbon and 13.3% Hydrogen. It’s molecular weight is
60.1 g/mol. Find the MOLECULAR FORMULA.
C
2
N
2
H
8
4. How many grams of the limiting reagent are consumed when 4.00 grams C
4
H
10
combusts with 5.0 L of O
2
at STP
7.14 g oxygen
5. in 375 mLs of 0.105 M NaClO
4
, how many atoms of oxygen?
9.48x10
22
6. How much kinetic energy is associated with a mole of helium at room temperature is moving 1.23*10 3 m/s? (hint:
J= kg*m 2 /s 2 ) g. 3.02 *10 3 J
7. Which of the following are in correct INCREASING order:
A. For frequency: Ultra Violet<blue<green
B. For wavelengths: Ultra Violet<blue<green
C. For Velocity: Ultra Violet< blue<green
D. For Energy: Infared<ultraviolet<xray radiation
E. A, C and D are correct
F. A, B and D are correct
G. B and D are correct
8.

rays are emitted from certain collapsing stars called hypernovas, one of the most powerful cosmic events. An astronomer records a

ray with a wavelength of 0.100 pm.
How many time faster is the frequency of these rays than ultraviolet radiation of 100. nm?
1.00* 10 6 s -1
9. A campfire with wood gives off blue glow with a
 max of
478 nm, what is the surface temperature?
C. 6060 K
10. The work function for silver is 6.66*10 -19 J. What is the threshold frequency?
C. 1.00 * 10 15 Hz
11. If you shine an extremely high frequency beam at a metal surface, what is the greatest possible theoretical velocity achievable by the ejected electron?
A. There is no limit, as long as you keep increasing the power on the laser, the energy in excess of the threshold
B. 3.00 * 10 8 m/s because that’s the speed of light
C. Approaching but never quite reaching 3.00 * 10 8 m/s
D. 0 m/s, high frequency means low energy so nothing will be ejected.
E. 0 m/s, you can’t eject electrons from a metal surface
F. Impossible to determine because we don’t know the intensity of the laser.
G. Impossible to determine because frequency isn’t related to the kinetic energy of an ejected electron.
12. Why don’t we consider the wavelength of macroscopic objects?
A. Their scale is greater than the height of the wave obscuring the wave
B. The wavelength is too long to observe compared to how far they are moving
C. The wavelength is too short to observe compared to how far they are moving
D. Because of the Rydberg principle they have no associated wavelength
E. Due to the Heisenberg uncertainty principle we cannot determine with enough accuracy their associated wavelength.
F. Their mass generates force that in turn counteracts the wave
13. Name K
2
CrO
4
potassium chromate
14. Give the formula for Aluminum Sulfide
Al
2
S
3
15. Give the electron configuration for neutral silver
[Kr] 5s 1 4d 10
16. Give the electron configuration for the silver cation
E. [Kr] 5s 0 4d 10
17. Provide the name for the compound with an empirical formula of H
2
N and a formula weight of 32.04 g/mol dinitrogen tetrahydride
18. Give the electron configuration for F -
A. [He] 1s 2 2s 2 2p 6
B. 1s 2 2s 2 2p 6
C. 1s 2 2s 1 2p 6
D. 1s 2 2s 1 2p 4
E. [He] 2s 2 2p 6
F. B and E
G. A and E
Extra Credit Multiple Choice:
19. Which of the following are in increasing order of shielding from the nucleus in a multi-electron atom?
A. 4s<3s<3p<3d
B. 1s<2s<3p<3d
C. 1s<2s<3d<3p
D. 2s<1s<3d<4s
E. 4d<3d<3p<4f
F. 1s<2s<3d<4s
G. All are equally shielded

20. What is the difference in the energy level diagram of a hydrogen atom and a multi-electron atom.
A. there is no difference; the number of electrons in an atom doesn’t change the diagram.
B. a hydrogen atom doesn’t have orbitals over the n=1 level since it only has one electron.
C. a multi-electron atom has more orbitals than a hydrogen atom since it has more electrons.
D. there is no shielding in the hydrogen atom, so the orbitals within a shell have different energies.
E. there is shielding in the hydrogen atom, so the orbitals within a shell have different energies.
F. there is no shielding in the hydrogen atom, so the orbitals within a shell have the same energies.
G. there is shielding in the hydrogen atom, so the orbitals within a shell have the same energies.
Short Answer
1) Give the electron configuration of Chromium. Explain how you arrived at this conclusion. [Ar]4s 1 3d 5
2) For each set of quantum numbers, give the missing quantum number possibilities, the number of orbitals that can have those quantum numbers, and the number of electrons that can be present. a) n=6 l=1 and 4 m s
=+1/2
i) m l
=? ii) number of orbitals? 12
+/-4, +/-3, +/- 2, +/- 1, 0, iii) Number of electrons? 12 b) n=3 m l
=-1, 0, 1 m
i) l=? 2, 1,0 ii)number of orbitals? 7
2
= +1/2 iii) Number of electrons? 17 c) n=5 l=4
i) m l
=? ii) number of orbitals? 9
+/-4, +/-3, +/- 2, +/- 1, 0, iii) Number of electrons? 18
3) Explain the difference between destructive and constructive interference. How does this relate to the Young’s double slit experiment?
Constructive interference adds the waves together making peaks higher and troughs lower. Destructive interference subtracts from each other cancelling each other out. Young’s Experiment- The patterns of constructive and destructive interference is what gives the patterns of light (interference pattners) and shows wave like behavior of light.
4) Explain the difference between a wavefunction and a probability density . Give the symbol for each in your explanation and also state what sign (positive or negative) each is allowed to be. Identify which graph is the wavefunction and which is the probability density for the particle in a box.
,
The wavefunction can be both positive and negative so it is A on the graph and is represented by the symbol

. It describes the movement of a particle. The probability density is

2 so it is always positive and is shown as B on the graph. It describes the likelihood of finding a particle in a particular area.
5) Given the following graph explain why the grass is green. (see front screen for a chart of color vs. wavelength). What would happen if you grew plants under green light? Why?

Chlorophyl absorbs red light refleting the green back at us.
6) An electron with a kinetic energy of 2.41*10 -19 J has its position known to within 2.122*10 -15 m. What is the uncertainty in the velocity? What would happen if your uncertainty in velocity increased?
2.73x10
10 m/s
Extra Credit Short Answer
7) Ionization occurs when an electron is ejected from an atom, aka it is so far away that it is no longer in any of the energy shells. Start with the Rydberg equation, and show all steps to find the ionization energy for a He +1 atom with its electron in the n=6 state initially.
2.42x10
-19 J