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Q & A: Why haven't neutrons decayed?

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Most recent answer: 09/27/2012
Q:
If neutrons decay in 15 minutes, why are there any neutrons after bllions of years? Why haven't they decayed?
- raad (age 11)
hyderabad andhra india
A:
Free neutrons decay in around 15 minutes. Binding neutrons into nuclei (especially the common 4He nucleus) stabilizes them. A free neutron can decay to a proton, an electron, and a neutrino, conserving energy. A neutron in 4He would have to get some additional energy to do that.

Mike W.

(published on 09/27/2012)

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