Monday, January 8, 2018

CHEM 418 Nuclear Chemistry, Winter 2018: Lecture 2 Nuclear Properties

A discussion on systematics of nuclear properties are presented.  Mass, mass excess, and mass distribution within the nucleus is presented.   Mass excess data are used to calculate energies in decays.  Equations for determining nuclear radii are provided.  Models that are used to describe the stability of nuclei are introduced.  Nuclear shapes and structures are introduced. The lecture time is 48 minutes.  There is a 3 minute supplemental lecture on the Brookhaven National Laboratory (BNL) Q-value calculator (Links to an external site.).  The Russian site Q-value calculator (http://nrv.jinr.ru/nrv/webnrv/qcalc/ (Links to an external site.)) has recently been unreachable.
The lecture is assigned on Saturday 6 January 2018 and due Thursday 11 January.

39 comments:

  1. Lecture 2 reviewed, but I don't see PDF quiz 2 on the Canvas assignment page?

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    1. PDF quiz 2 will be posted today. I apologize for the delay. If this delay causes an issue for the submission date please let me know.

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    2. Its all good. Quiz 2 submitted on Canvas.

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  2. Lecture 2 reviewed and PDF quiz 2 emailed.

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  3. Lecture 2 reviewed and PDF quiz sumbitted

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  4. I have reviewed Lecture 2 and submitted the quiz by both email and canvas.

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    1. thanks for PDF quiz 2. Please review binding energy.

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  5. Lecture 2 viewed and PDF quiz 2 submitted through email.

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  6. Lecture 2 reviewed and quiz 2 emailed

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    1. This comment has been removed by the author.

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    2. thanks for the PDF quiz. One small error on the Q value for 210Po alpha decay

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  7. Done with lecture, and I finished the pdf quiz. I was a bit unsure on problem 3 though. Since we are given a range of r_o values, I only checked the isotopes that had a value of 6 fm within the resulting range of R for each. I wasn't sure which r_o value to use or whether to round or not so this is what I did.

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    1. calculate the values within the range of r_o values, which is what you did. Or set the radius at 6 fm, then use the minimum and maximum r_o values to determine the range for A.

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  8. Done with lecture, submitted the quiz. I was also unsure for question 3, so I checked to see if any value of r_o, 1.1 through 1.6, would give a radius of close to 6. I submitted it on canvas.

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    1. that is the correct way to answer the question.

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  9. Lecture 2 watched and PDF quiz submitted through canvas

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  10. Lecture 2 has been viewed, and quiz was submitted through email.

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  11. Lecture 2 quiz(emailed) and lecture finished.

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  12. This comment has been removed by the author.

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  13. lecture 2 watched, PDF quiz submitted through canvas.

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  14. Finished lecture 2, and submitted the pdf quiz on canvas.

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  15. Finished lecture 2, emailed PDF quiz.

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  16. Lecture 2 reviewed and quiz submitted via email and canvas.

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  17. I have reviewed Lecture 2 and submitted the quiz via email.

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  18. I reviewed Lecture 2 and have submitted Quiz 2 by email as a PDF attachment. Still unable to complete the digital signature or use the submit form button in the top right.

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    1. are you downloading the form first then filling it out? I am able to enter your pdf quiz into the database as you submitted it.

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    2. Whenever I click on the link to take the quiz, my computer automatically asks to download it. I do not know if there is a workaround to this. But if you are having no trouble entering my quizzes to the database, then I will not worry about it.

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  19. Lecture 2 and quiz 2 reviewed and Submitted.

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  20. I reviewed lecture 2 and submitted quiz 2 through email. Thank you for the supplemental lecture.

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  21. Viewed and submitted through e-mail via button on the form. Supplemental lecture helped a lot!

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    1. I am happy to hear the additional lecture helped.

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  22. sent the quiz in before 12 but forgot to do the blog post. whoops.For the bonding energy equation why is it that coulombic forces provide a negative term which would lower bonding energy? Wouldn't proton repulsion cause energy to increase?

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    1. No worries about the posting time!

      The binding energy is relative to the nucleus. A larger binding energy means a more stable nucleus. The Coulombic force due to proton-proton charge repulsion acts to destabilize the nucleus, so it decreases the binding energy.

      This is one reason the proton to neutron ratio is an important term for nucleus stability. If one looks at the stable isotopes, this ratio changes. It is about 1 with the lighter elements (i.e., 12C) and shows neutron excess in the heavier elements (i.e., 208Pb).

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  23. Thanks for all the comments and PDF quizzes. The answers to PDF quiz 2 are now posted. Most all responses are correct! Many thanks.

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  24. Sorry I just realized I have to post here.
    I hope the submission is successful - Ryan Cheung

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