Take the 2-minute tour ×
Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. It's 100% free, no registration required.

Is the half-life of Primordial Nuclide determined only by the age of the earth? Or are their other age defining considerations? The point of the question is to know that the only reason that we have a determination of the half-life of Primordial Nuclide is by its comparison solely to the lifespan of the earth, or if their is any other foundation for determining the half-life.

I want an alternate method of determining the duration half-life of a Nuclide. Specifically Primordial Nuclide. The only method that I know about right now is through visual measurement.

share|improve this question

closed as unclear what you're asking by rob, Brandon Enright, Jim, John Rennie, Chris White Jun 27 at 23:51

Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question.If this question can be reworded to fit the rules in the help center, please edit the question.

3  
The half-life of any nuclide is independent of the age of earth; it is what it is. –  Kyle Kanos Jun 27 at 16:30
    
    
@rob That question is to find the "How" to a considered radioactive decaying process. This question is related to "When/Duration". And the measurement of that duration. So you are in error. –  Only he is good. Jun 27 at 17:16
    
@KyleKanos What you say is true. The point however is "NOT" to redeem a value to a half-life by the equation (Time of Earth Creation)+(Lifespan of Earth)=half-life of Primordial Nuclide. But by another means to determine its lifespan. It may be what it is, yet Nuclides with half-lives less than 24 hours but more than 1.0 hour do exist and can be proven by visual results. Therefore what is seen stands as its own testimony, for others can see it as-well. With Primordial Nuclide we have a visual record as-well but it should not stand with the same testimony for what test visually proves duration? –  Only he is good. Jun 27 at 17:28
    
I have no idea what message your comment to me is trying to convey (it seems to be completely irrelevant to my comment). –  Kyle Kanos Jun 27 at 17:32

1 Answer 1

up vote 2 down vote accepted

An age estimate of the Earth is not used to determine half-life of an isotope.

Instead, the rate of decay (decays per time unit) relative to the amount of sample (number of nuclei), and first order kinetics are used to determine half-life.

For example, in 1932 Kovarik and Adams calculated the Uranium-238 half life based upon 24,770 alpha particle decays per second per gram of uranium.

See The Isotopic Constitution of Uranium and the Half-Lives of the Uranium Isotopes. I and references cited therein for historical and experimental information.

share|improve this answer
    
Is this method you speak of "first order kinetics" used to valuate this statement "Around 99.284% of natural uranium is uranium-238, which has a half-life of 1.41×1017 seconds (4.468×109 years, or 4.468 billion years)" Found (en.wikipedia.org/wiki/Uranium-238)? –  Only he is good. Jun 27 at 18:12
1  
It applies to the "uranium-238, which has a half-life of 1.41×1017 seconds (4.468×109 years, or 4.468 billion years)" part, but it is unrelated to the "Around 99.284% of natural uranium is uranium-238" part of the statement. –  DavePhD Jun 27 at 18:16
    
I accept this answer not because I know its the truth, but because it fulfills the format of the question. –  Only he is good. Jun 30 at 15:01
1  
@Onlyheisgood. see the following publication of Rutherford's 1899 measurement of Thorium's half-life: chemteam.info/Chem-History/Rutherford-half-life.html This is a good example of how half-life is experimentally determined. –  DavePhD Jun 30 at 15:10
    
@Onlyheisgood. I added a reference that explains in more detail how Uranium-238 half life was first determined. –  DavePhD Jul 1 at 13:54

Not the answer you're looking for? Browse other questions tagged or ask your own question.