Pair production and antimatter
In 1932 Carl Anderson discovered the positron.
The positron is a particle of antimatter and it was the first known particle of antimatter to be found. It has the same mass as an electron but a positive charge.
A high-energy gamma ray passing close to the nucleus of a heavy atom can turn into two particles – an electron (matter) and a positron (antimatter).
When a particle meets an antiparticle they destroy each other producing a flash of energy – usually gamma rays.
Electrons and positrons annihilating each other have been seen in the lab.
