Assertion: gamma ray's energy | /r/HasProperty | 5 mev
Facets:
Source sentences:
text: Pair production: Requires high energies ( > 1.02 MeV, usually > 5 MeV); incoming photon ejects an electron and a positron, but positron quickly encounters an electron and annihilates to two 0.51 MeV gamma rays (E=Mc2).
text: Photoelectric effect: Can occur at low energies ( < .5 MeV); incoming photon ejects an electron.