Assertion: mev gamma ray | /r/HasProperty | e=mc2
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).