Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: [Phys-l] question on radioactivity of Tc and Pm



Remember when I posted my Philosophy 1 nugget?

WC, your answer is one level further than necessary.

bc, maybe should retract the above.

p.s. a superficial perusal of the Wiki. shows it does partially deal w/ a level above the ultimate explanation. BW's assertion, at our level of knowledge, may be easily proved w/o creating the necessary 70+ additional examples.

p.p.s Question; why do things fall? Because they have a higher potential energy -- A step has been skipped.
William Maddox wrote:

From: WC Maddox

As a starting point calculate the binding energy using the semi-empirical mass formula in Wikipedia.

End Message




At 12:25 AM 3/5/2007, you wrote:



I would be interested to learn why these two elements are radioactive
even though they have relatively low atomic numbers.

This is true of Tc especially, for which Z = 43.
For Pm Z = 61.

Subsequent elements are not radioactive until one reaches Po (Z =84)
and all subsequent elements.
What is special about Tc and Pm ?



regards,
eric scerri


P.S. I cover basic nuclear physics and nucleosynthesis in the final
chapter of my new book but was not able to answer this nagging question.


------------------------------------------------------------------------
------------------------------------------------------------------------
-------------
The Periodic Table: Its Story and Its Significance, by Eric Scerri,
Oxford University Press, 2007.

"An absolutely gorgeous book. I put it on my bedside table
and then stayed up half the night reading it - it is immensely
readable."
---Oliver Sacks, author of The Man Who Mistook his Wife
for a Hat, Awakenings etc.
------------------------------------------------------------------------
------------------------------------------------------------------------
---------------------------------------------

Dr. Eric Scerri
Department of Chemistry & Biochemistry,
Charles Young Drive,
Los Angeles,
CA 90095-1569.

310 206 7443
fax: 310 206 2061

UCLA faculty web page: http://www.chem.ucla.edu/dept/Faculty/scerri/

Editor of Foundations of Chemistry,
http://www.springer.com/sgw/cda/frontpage/0,11855,4-40399-70-35545882-
detailsPage%253Djournal%257CmostViewedArticles%257CmostViewedArticles,
00.html

International Society for the Philosophy of Chemistry,
http://ispc.sas.upenn.edu/



_______________________________________________
Forum for Physics Educators
Phys-l@carnot.physics.buffalo.edu
https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l


_______________________________________________
Forum for Physics Educators
Phys-l@carnot.physics.buffalo.edu
https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l