Answer to Question #167211 in Molecular Physics | Thermodynamics for Afraid

Question

What is positronium system.

Answer 1

Positronium (Ps) refers to a system consisting of an electron and its anti-particle, a positron, bound together into an exotic atom, specifically an onium. The system is unstable: the two particles annihilate each other to predominantly produce two or three gamma-rays, depending on the relative spin states.