Physics 198 Lecture Notes - Lecture 11: Pauli Exclusion Principle, Proton Decay, Gamma Ray
Document Summary
Nuclei that have too many protons or neutrons are less stable. Proton rich nuclei decay by positron emission or electron capture. Neutrino + atom -> atom with 1 more proton and 1 less neutron + 1 electron. Mass of an electron + mass of a proton < mass of a neutron. Neutrino = also a lepton (this reaction is mediated by the weak force) Also generates some kinetic energy the bar means anti (anti neutrino which is an anti-lepton) Half-life of neutron ~ 10. 25 minutes does not happen for free protons. Double occupancy for each energy level (different spin) No 2 objects can have the same quantum numbers (pauli exclusion principle) Excess energy available, so proton can be converted to neutron by releasing a positron and a neutrino, and some energy (radiation) Done to reach a more energetically stable form. (electron capture) (positron capture) Alpha: emission of he nucleus: zp + zn.