Why is C-14 Radioactive Despite Low N/P Ratio?

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Discussion Overview

The discussion centers on the radioactivity of Carbon-14 (C-14) in relation to its neutron-to-proton (n/p) ratio, specifically addressing why C-14 is radioactive despite having an n/p ratio that is less than 1.5. The conversation explores theoretical aspects of nuclear stability and the concept of "magic numbers" in nuclear physics.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • Some participants question the validity of the n/p ratio as a definitive indicator of nuclear stability, suggesting there is no "magic rule" governing radioactivity based solely on this ratio.
  • Others argue that while there are no stable nuclei with an n/p ratio greater than 1.5, it does not imply that all unstable nuclei must have an n/p ratio exceeding this threshold.
  • A participant cites Lead-207 as an example of a stable isotope with an n/p ratio of 1.524, challenging the notion that the n/p ratio is a strict rule for stability.
  • Another participant introduces the concept of "magic numbers," indicating that certain configurations of protons and neutrons lead to exceptional stability, which may also apply to C-14.

Areas of Agreement / Disagreement

Participants express differing views on the relationship between n/p ratios and nuclear stability. There is no consensus on the applicability of the n/p ratio as a rule for determining radioactivity, and the discussion remains unresolved regarding the implications of "magic numbers" and their exceptions.

Contextual Notes

The discussion highlights limitations in the understanding of nuclear stability, particularly regarding the n/p ratio and the exceptions presented by certain isotopes. The nuances of the "magic numbers" concept and its implications for stability are also noted but not fully explored.

assassinsdoc
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Why c - 14 is radio active though n/p ratio is less than 1.5?
 
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That is not a rule. Most radioactive elements do not have n/p > 1.5. That's a myth
 
Do not confuse the statement "There are no stable nuclei with n/p > 1.5" with the statement "All unstable nuclei have n/p > 1.5". See the difference? The first one is true. The second one most definitely isn't.
 
dauto said:
Do not confuse the statement "There are no stable nuclei with n/p > 1.5" with the statement "All unstable nuclei have n/p > 1.5". See the difference? The first one is true. The second one most definitely isn't.
Lead-207 is (experimentally1) stable with 82 protons and 125 neutrons, 125/82=1.524.
There are a few other examples, see the linked list.
 
mfb said:
Lead-207 is (experimentally1) stable with 82 protons and 125 neutrons, 125/82=1.524.
There are a few other examples, see the linked list.

That's exactly my point. This rule is just an approximate rule of thumb...
 
thank you!
I've studied in class about something called 'magic numbers' where nuclei having 2, 8, 20, 28, 50, 82 or 126 protons or neutrons or both (separately) are exceptionally stable compared to their respective neighbouring nuclides. So, they too make an exception.
 

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