Simplify the following text for a Grade 12 native English-speaking person.
Original: When an electron collides with a positron , both particles may either scatter off each other or be totally annihilated , producing a pair ( or more ) of gamma ray photons .
Simplified: When an electron collides with a positron , they may scatter off each other or be totally annihilated , producing a pair ( or more ) of gamma ray photons .