Sunday, January 3, 2016

CHEM 418 Nuclear Chemistry, Winter 2016: Lecture 1 Introduction and Chart of the Nuclildes

The class outcomes, expectations, and grading are explained.  A history of radioelement discovery and radiation research is presented. The Chart of the Nuclides and Table of the Isotopes are discussed and used.  Atomic properties, nuclear nomenclature, X-rays, types of decays and physical forces are introduced. The lecture is assigned on Monday 4 January and due Saturday 9 January. 

37 comments:

  1. Lecture 1 is really interesting, and I know how to use the chart of the nuclides and table of the isotpoes now.
    I sent the lecture 1 pdf quiz as an attachment through email.
    Thank you

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  2. Enjoyed both parts of lecture 1. Quiz is submitted through email as an attachment. Thank you.

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    1. thanks for the PDF quiz. Please see my e-mail comments.

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  3. This comment has been removed by the author.

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  4. Submitted Quiz 1 via email

    -Faruq

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  5. I have received some PDF quizzes and I have some general comments.

    Quesiton 3 on PDF quiz 1 make sure you use the half life for 261Rf, not 261mRf. The first half life is 261mRf, the second is 261Rf. You can review the chart information on page 44 to verify.

    For question 5 see the guide on page 44 of the chart of the nuclides the guide. On the right side of the page is a column of isotopes. The 4th one down, 138La, is an example of naturally occurring or otherwise available but radioactive. In the chart of the nuclides this is designated by a black bar across the top of the box with the isotope in white; as is shown for 138La in the example.

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    1. Thank you, this helped clarify things for me.

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  6. Submitted the Lecture 1 PDF Quiz through the Canvas email.

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  7. Completed and sent as an email attatchment

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    1. thanks Bryan. I have your pdf quiz, please review my comments.

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    1. john

      Please resubmit. I did not receive it on the canvas site.

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  9. Lecture viewed, and Quiz submitted via email.

    I am still having troubles using the Chart of Nuclides, and was confused with the varying information across different sources. For example, when working on question 3, the half life was reported as different values across different sources of charts. This could just be due to the dates of updating information.

    I am also having troubles grasping fission products and fission yields, but hopefully, as I continue along this course, I will soon master these concepts.

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    1. Jessica

      Excellent observation!! The data can vary with sources. As with any source you should reference where you got the information. For this PDF 0 I would expect you to use the distributed chart of the nuclides, 17th edition. For question 3 the half life of 261Rf is 4.2 seconds, with can be used directly to find the decay constant from the equation:

      decay constant (s-1) =ln2/half life (s)

      If one uses the data from the NNDC database (http://www.nndc.bnl.gov/chart/chartNuc.jsp)

      the 261Rf half life is 1.9 seconds, so a different decay constant.

      The fact you noted this is excellent and is one of the reasons I used this isotopes. As for fission products and fission yield, this will be explained in much more detail in the lecture on fission. I am certain you will understand that lecture material.

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    3. Thank you this Helped me to figure out what I did wrong with question 3 because I put down the half life instead of the decay constant.

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    4. Quick question off based from Jessica's question.

      Since we now know the Half Life of Rf261 is 4.2 seconds what is the other number on the Nuclide chart.


      The table gives something like this.


      Rf261
      1.3 min | 4.2 seconds
      α 8.28 | α 8.52
      SF? | SF
      - - - - -
      261.10877

      taken from pg 79

      I understand that the column on the left may or may not be a Spontaneous Fission Product hence the 'SF?'. But aside from reading questions on the Blog how do know which number is the correct Half Life for the given situation? Without guessing haha...

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    5. the left side provide the half life for the metastable isotope, 261mRf. The right side is the data for 261Rf, which should be used in the question. We will discuss metastable isotopes in more detail during the lecture on gamma decay.

      Metastable isotopes are in the excited nuclear state. Generally excited nuclear states have half-lives on the order on nanoseconds to picoseconds. In some cases, mainly due to spin and parity transitions, the nuclear excited states can be long lived compared to the nsec or psec states. These are the metastable states. A well known examples is 99mTc, the workhorse of radiopharmaceuticals (https://en.wikipedia.org/wiki/Technetium-99m).

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  10. Professor,
    I enjoyed the lecture, especially the little history bit you did in the beginning (names of radioactive elements make more sense when you know the people involved!). I emailed you quiz 1 on canvas.

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    1. thanks for the PDF quiz. I responded to your email.

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  11. Quiz 1 submitted via emial

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    1. Thanks for your submission. Please see the comments I sent

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  12. Lecture done and quiz sent as email attachment.

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  13. Submitted the quiz through email
    -Taylor Posey

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  14. I'm confused on Why 243Cm is not the longest lived isotope when it has a half-life of 29.1 years while the next closest one 244Cm has a half-life of 18.1 years.

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    1. The possible isotopes on the list go from 242 to 250. Within this group there a few that are longer lived than 243. You can resubmit the PDF quiz.

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  15. Never mind i see that I over looked the E in 1.5E7.

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  16. As a reminder, the information contained in the Chart of the Nuclides is explained in the guide for using the chart of the nuclides, which is on page 44 of the book. This is the same information that is described in Lecture 1, part 2 beginning on slide 8. If you are viewing this on video, this section starts around the 11th minute.

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