This lecture covers the fundamental equations that describe the decay of radionuclides. Basic equations and their utility are presented. Equations for mixtures, equilibrium, and branching of radionuclides are covered. Examples are provided for error evaluation from counts, activity determination, evaluation of half life, and lifetime of isotopes. Discussion of natural radiation and dating are given. Examples are provided for dating from 238U, 14C, and the Oklo reactor.
PDF Quiz 3 is posted.
ReplyDeleteComment on Quiz 3, question 1.
ReplyDeleteThis question is related to slide 9 of lecture 3 (Expected Standard Deviation).
There is an inherent error due to the number of counts. As shown on the slide if you have M total count, the expected standard deviation is the square root of M. As shown on the slide there are different errors expected for the total number of counts.
If you have 1000 counts in a minute, the expected standard deviation is 31.6. This means
that if I counted the sample a number of times, each for one minutes, I would not expect the identical value of 1000 each time. Based on the standard deviation I would expect the counts to be 1000+/- 31.6; 969 to 1032. I would not expect a total count of 1150, this is well outside the standard deviation range.
Please let me know if you have any questions on this.
Thank you for the clarification! That definitely help make the question clearer for me
DeleteLots of equations in this lecture series. Good thing there's the internet and data/cheat sheets to keep them handy when performing work.
ReplyDeleteThanks for the comment. Including a page with a synopsis equations presented in the lecture is an terrific idea. This would make it easier to review and provide a data sheet as you suggested. i will put this in future lectures as needed.
DeleteThis is a great suggestion that you made for us to do, but would also be helpful to have you include at the end of the lecture to ensure we recorded all of the equations and their purposes correctly. :)
DeleteLecture was great. Since there are many equations, it requires more practice for sure yet i enjoyed it. Quiz question one was confusing at first until i saw your comment so thanks.
ReplyDeleteThanks for the comment. I added the clarification after receiving the first PDF quiz response. It was obvious this section was unclear and needed some further description.
DeleteThe lecture was great as always as well as it was interesting which is what I like about this class. This section of the class is something I will really need to study with all the equations given but still do able. The first question of the quiz was a bit confusing but with your comment I was able to figure it out.
ReplyDeleteThanks for the comment. I am happy the comment was useful.
DeleteI have submitted quiz 3. The derivations of the equations in the lecture were straightforward and well presented.
ReplyDeletethanks for your quiz and comments
DeleteEven though it was a minor part of your lecture, I was interested in learning more about the Oklo reactor. I find it awesome that a self sustaining nuclear reactor existed on earth. According to the page on Wikipedia, the reactions occurred about 2 billion years ago. It also created about 100kW or about 134 horsepower of thermal power.
ReplyDeleteIt is interesting. Not much energy but the decrease in 235U due to the fission was observed. If you are interested you can research Oklo for a final project.
ReplyDeleteI've been curious about the reliability of radiometric dating, and it seems that it rests on the assumptions listed on slide 22 that no Daughter atoms were present at formation of the system in question and that the system remained closed during the entire decay process. The readings mention that these assumptions are rarely accurate and that corrections need to be made for contamination. How are these corrections typically made, and how reliable can they be? Particularly with respect to the well-known example of this technique being used to measure the age of the Earth itself.
ReplyDeleteIn any case, I enjoyed this lecture both for the encompassing discussion of the mathematics behind Radioactive decay and the tangent on dating that it sent me on.
some of the correct methods include the use of 2 dating isotopes. For example one can date with 235U and 238U. The concepts are the same and two dates will result, which can be used to improve confidence.
DeleteThe lecture was packed with a lot of information regarding mathematics. It was interesting to see the different equations that entails decay and dating, I was really intrigued with the ERG Program and Bateman Program used to calculate different decays. I also was fascinated with the Oklo reacter and how it is a natural self-sustaining nuclear reactor.
ReplyDeleteThanks for the comments. I hope the use of the program provided a good example for the utilization of equations.
DeleteThis lecture was filled with a lot of information, however having examples of the applications of the equations presented were helpful.
ReplyDeletethanks for the comments! I will make sure examples are included in future lectures.
ReplyDeleteI finished the lecture and submitted the quiz. This was my favorite topic yet. Thank you for the additional comment in the blog; it really clarified the homework.
ReplyDeleteI have already finished the lecture and submitted the quiz, too. This lecture definitely had a lot of equations and examples. Thanks for including all the example, they really help me grasp what the equations are used for.
ReplyDeletethis lecture was definitely harder than the previous ones. I had to put more time in and think about certain concepts. A lot of equations too.
ReplyDeleteAnother very interesting lecture. It is amazing the capabilities that have been discovered and what can be calculated even with the amount of random/environmental error possible. Even then it is still possible to calculate and take these factors into consideration (something a lot of other forms of chemistry still have a hard time understanding, let alone calculating to adjust for this error).
ReplyDeleteCannot wait for the next lecture!
thanks for the comments
DeleteForgot to comment here sorry, but I watched the lecture
ReplyDeletethanks!
DeleteSorry I forgot to comment! I watched the lecture video!
ReplyDelete