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Tuesday, June 8, 2010

Possible Lab Final Scenarios

Double/Single Slit
Diffraction Grating
LRC/RL CIRCUITS!!!!!!!
OSCILLISCOPE LAB!!!!
Lenses
Emission Spectra

review and memorize the circuit diagram for the LRC/oscilliscope/function generator lab!!

Good luck guys! especially Lauren cause you actually read these

Tuesday, June 1, 2010

just in case anyone cares

I'm sure you chem people know about the Aufbau Principle which basically states that electrons fill in the lower energy levels first and then move their way up from there. It is one of the most basic theories that is the basis for all of chemistry. Well, the Stanford Particle Accelerator Lab has just discovered with their X-ray picoscope (which is an actual thing I didn't make it up it means a "microscope" that uses particles with a wavelength of 10^-12) which can actually watch chemical reactions occur at the atomic level, that they in fact do not follow this principle, but randomly fill in whatever orbital is available...so in conclusion Chem sucks; Physics rocks!

Quantum Numbers cont'd

So in order to use this procedure with particular atoms we have to start with Hydrogen because we know that Hydrogen has 1 electron, which is in the n = 1 shell. So beginning with hydrogen:
Element: Hydrogen, # of electrons = 1
n = 1, l = 0, m_l = 0, m_s = +1/2 (or you could write n = 1, l = 0, m_l = 0, m_s = -1/2), but since there is only one electron you only write one of these two options.
Now as we go down and continue to add these numbers the number of electrons will coincide with each element. The next one being Helium because it has two electrons:
Element: Helium, # of electrons = 2
n = 1, l = 0, m_l = 0, m_s = +1/2
n = 1, l = 0, m_l = 0, m_s = -1/2
Then, you continue down the line:
Element: Li, # of electrons = 3
n = 1, l = 0, m_l = 0, m_s = +1/2
n = 1, l = 0, m_l = 0, m_s = -1/2
n = 2, l = 0, m_l = 0, m_s = +1/2

So basically you just list everything in order and for each electron you count them and put the atom by the # of electrons it has

So write the configurations for Oxygen

Quantum Numbers

Ok so it sounds like some of you are confused about quantum numbers so here we go:
Each set of quantum numbers, which will be a set of four numbers separated by commas, represents one electron and said electrons "position" in the atom. According to the Pauli Exclusion Principle, which you should know, no two electrons can have the same 4 quantum numbers. The quantum numbers each have rules discussing which numbers they are "allowed" to be, which are as follows:
n = 1, 2, 3, 4,...,infinity
l = 0, 1, 2, 3, ... , n - 1
m_l = -l , ... ,+l
m_s = -0.5, +0.5
Therefore if I have a certain n number like n = 3 I can have electrons with angular momentum numbers, l numbers, up to n - 1; which for us is 3 - 1 = 2. Thus, the L-numbers possible are l = 0, 1, 2 and thats it. IN EACH OF THOSE I can have a magnetic quantum number, m_l-number, going from -l to +l. Then in each of those we can have an electron spin of -1/2 or +1/2. So for n = 3 we have these possible electron positions:
n = 3, l = 0, m_l = 0, m_s = +1/2
n = 3, l = 0, m_l = 0, m_s = -1/2
notice that these two electrons have all the same quantum numbers except for the m_s number, or the electron spin number. Continuing on:
n = 3, l = 1,
now since l = 1 my m_l numbers can either be -1, 0, +1
n = 3, l = 1, m_l = -1,
now there are two more possibilities for m_s:
n = 3, l = 1, m_l = -1, m_s = -1/2
n = 3, l = 1, m_l = -1, m_s = +1/2
and when m_l = 0:
n = 3, l = 1, m_l = 0, m_s = -1/2
n = 3, l = 1, m_l = 0, m_s = +1/2
and finally when m_l = +1:
n = 3, l = 1, m_l = +1, m_s = -1/2
n = 3, l = 1, m_l = +1, m_s = +1/2

Now try and write all of the configurations for when n = 3, l = 2


Monday, May 31, 2010

Studying?

I'm starting to worry because no one is writing any questions on here and no one has tried to contact me with questions....are any of you studying?

Saturday, May 29, 2010

Problem 32.3 (Assignment 14)

Question: What is the nuclear radius of 197,79 Au?

Gold (Au)
Atomic Number: 79
Atomic Mass: 197

I figured out the answer to be 7*10^-15 m

but the answer is in meters, and mastering physics wants it in fm.
how do I convert it to fm?

Thursday, May 27, 2010

Final Review Session

The final review session will be on Friday, June 4th from 8am - 12:00pm. If there are any other times you would like to request then please just let me know. Thanks
Dante

Conceptual Questions

1. What happens to the electric field and the capacitance when a dielectric is added to a capacitor? Why? Draw a diagram to illustrate your explanation.

2. Compare and/or contrast electric potential energy and electric potential. Conceptually, is there a difference or are these just two names for the same thing? Explain.

3. On the passenger side all automobiles the side mirror states “object are closer than they appear.” What type of mirror is used on the passenger side? Why is it necessary to have this warning?

4. What is resonance frequency? What are its effects on the elements in an RLC circuit as well as the entire circuit itself?

5. Can anything go faster than the speed of light? Explain.

6. What is the twin paradox.

7. What is the result, as predicted by geometric optics, of light going through a double slit? Is this prediction correct? Explain.

8. What does the “phase” of a circuit mean?

9. Explain, at the subatomic level, what is happening inside the gas tubes that you used for the line spectra lab?

10. a) Compare and/or contrast fission and fusion. Conceptually, is there a difference or are these just two names for the same thing? Explain. b) Which, if any, can be utilized to create energy by humans?

11. Explain how a nuclear bomb works in terms of the radioactive source. Why does this process release SOOO much energy?

12. What is an electron-volt? Why is it used?

13. a) Compare and/or contrast the Bohr model of the atom and the quantum-mechanical model of the atom. Conceptually, is there a difference or are these just two names for the same thing? Explain. b) Where and how are each used?

14. What is an interferometer? What does this device tell us about light?

Exam III and Final Review

Suggested Problems: 19-31, 19-79,20-33, 20-57, 21-45, 21-60*, 21-93, 22-47(764), 22-65 (766), 22-73 (766), 22-79 (767), 22-83 (767), 23-25 (799), 23-30 (799), 23-67(801), 23-81(802), 24-79(836), 24-69(835), 24-59(835), 25-57(867), 25-97 (869), 26-35, 26-55, 26-6126-101, 27-51, 27-69, 27-89, 28-71 (968), 28-63(968), 28-79 (969), 29-77, 29-63, 30-77(1033), 30-81(1033), 31-63(1070), 31-70(1070), 31-31(1068), 32-21 (1107), 32-40(1108), 32-51(1108), 32-77(1109), 32-65(1109), 32-71 (1109)

*a dielectric has been added to the 9.50 mF capacitor with k = 3.2


Thursday, May 20, 2010

CH 30 & 31 Practice Problems

Dante assigned the following practice problems in SI for chapters 30 & 31

CHAPTER 30:
# 55, 73, 78, 81

CHAPTER 31:
# 21, 31, 63

=)

Monday, May 10, 2010

Chapter 28 Practice Problems

28-5, 28-17, 28-21, 28-36, 28-44, 28-63, 28-71, 28-79