Hadron Epoch
Quarks bind into protons and neutrons. Matter gains stable building blocks for atomic nuclei.
As the universe continues to cool, quarks can no longer move freely. They bind together, forming protons and neutrons. For the first time, matter gains stable composite particles.
Most quarks and antiquarks annihilate each other, leaving a small excess of matter. This imbalance is critical. It ensures that matter survives rather than cancelling itself out entirely.
The hadron epoch establishes the basic building blocks of atomic nuclei. Structure is still impossible, but permanence has begun.