Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The lifetime of an unstable nucleus

  1. Jan 13, 2013 #1
    protons and neutrons interact with each other with the strong force, which is very strong

    however, there are many unstable nucleus which have a lifetime in the order of millions of years

    this is quite strange

    the time scale of strong interaction is many many orders smaller than that of the lifetime

    how is this possible?
  2. jcsd
  3. Jan 13, 2013 #2
    you are confusing weak decay with strong interactions.
  4. Jan 13, 2013 #3
    what is the force responsible for the decay of Ur?

    weak interaction or strong interaction?
  5. Jan 13, 2013 #4
    By what reaction it decay.that is the answer.
  6. Jan 13, 2013 #5


    User Avatar
    2017 Award

    Staff: Mentor

    Beta decays are always weak (quark numbers are not conserved).
    Alpha decays have a different issue: Those alpha particles do not have enough energy to escape in a classical way - they have to tunnel through a potential barrier, and the tunneling probability can be very small.
    Gamma decays can be long-living, if they do not have a (significant) dipole moment, and require the emission of multiple photons at the same time. And, of course, the electromagnetic interaction is weaker than the strong interaction.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Threads - lifetime unstable nucleus Date
B Why is Carbon-14 Unstable? Nov 28, 2017
A Why lower limits on proton decay lifetimes depend on channel Dec 1, 2016
I Relative Mean lifetime of decays Jun 21, 2016
Proton decay lifetime prediction SU(5)? Jul 25, 2015
Alpha lifetime of lead? Nov 13, 2014