45107cbe_s___Physics___Particle_Physics__Answer
[Date Answered] May 19, 1999 [Questioner (age, location)] Anna (Pennsylvania, USA) [Question] What is a pi-meson? [Answer] 
A pi-meson, or pion, is a sub-atomic particle composed of a quark, and anti-quark, and gluons. These particles are now considered the building blocks of the Universe. (Atoms were originally thought to be the building blocks.)
Quickie Questions - Physics - Particle Physics
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