For Friday's quiz (Feb 6) consider the following points on which to focus:
1) An understanding of the component nature of atoms. What are atoms made of? Roughly how big are atoms? What determines the mass of atoms? Why is it so difficult to explain the trends in the size of atoms and so straightforward to understand their mass? Quiz questions will focus exclusively on the lighter atoms, i.e., H to Ne (hydrogen to neon). You should know their "mass numbers" and the mass numbers for other important atoms in that range, i.e., H and D, He, Li, C, N , O and Ne. (D is deuterium.) There will be no questions on ions or on isotopes other than deuterium.
2) An understanding of the macroscopic, or phenomenological, definition of temperature. What is the key property, on a grand scale, that we would like temperature to have? When two objects have the same temperature is there any (net) heat flow between them?
3) An understanding of the relationship between what we call temperature and the microscopic character of molecules or atoms in an ideal gas. What property of the molecules or atoms is proportional to the temperature. What does T= absolute zero mean? What temperature scale is most helpful in revealing the relationship between atom motion and temperature? etc. Be able to work problems related to this.
4) For a string stretched between two fixed points, you should have an understanding of the pattern of allowed frequencies for pure modes (standing waves), and the ability to sketch some of the lowest frequency modes. See for example: http://hyperphysics.phy-astr.gsu.edu/hbase/Waves/string.html (Don't worry about all the math there. Just have a clear understanding of the relative frequencies of pure modes and how to illustrate what the look like.)
I think that is everything. If I think of anything else I will post it here before 10 PM tonight; also I will respond to any questions or anything you post tonight in the morning. (I would encourage you to check this in the morning and see what questions, answers and comments have been posted.)
Please feel free to post any questions or comments here. If you think you understand something but you are not sure, feel free to test your understanding via a post here.
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what exactly do you want us to know about deuterium?
ReplyDeletenataly -
ReplyDeleteJust the most basic things.
What is it comprised of?
What is it's mass?
How does it's size compare to atoms very similar to it?
Let us know if this isn't clear.
what formulas are we going to need for this quiz?
ReplyDeleteIs it okay if we just know the atomic masses (mass numbers) roughly? Like Oxygen as 16, Neon as 20 and so on? Or do you want us to know a more specific weight based on the mass of protons/neutrons as 1.67 x 10^-27 kg?
ReplyDeleteParts 1) and 2) above don't really require any formulas
ReplyDeletePart 3) above post describes one formula that may be helpful. (relationship of Temp to...)
In Part 4) there's isn't really a formula, just know the pattern of allowed frequencies.
Dear Caitlin,
ReplyDeleteJust roughly, as you specified, 16, 20 etc, is fine.
Also, just that deuterium is one proton and one neutron, has a mass number of two, but has only one electron (like hydrogen).
I hope someone sees this, I was wondering if someone could post a little study guide of things we should know for the midterm, so we can start preparing for it this weekend? thank you!
ReplyDeleteSara - I can try and post a list of things to study by later today.
ReplyDeleteIn the meantime, I would go back to the homework and quizzes and look at each problem and try to understand the principle behind it.
i.e. don't stress over finding the exact number of calories burned while riding a bike up a hill, but instead focus on understanding how work relates to kinetic and/or potential energy.