Baryonic matter

Baryonic matter is a type of matter that has a charge and spin opposite to Antimatter. When meeting antimatter, it will explode along with the baryonic matter in a so-called annihilation. Our local civilization is entirely made of baryonic matter, but has produced several nanograms of antimatter within traps that disable annihilation. If the universe was made up of half-antimatter and half-matter, then they would have all detonated leaving nothing except for radiation behind, so the theory is that either there is a third substance that stops antimatter-matter annihilation, or somehow more matter exists than antimatter.

Properties
Baryonic matter is usually very large compared to antimatter, with baryonic particles being up to 20 orders of magnitude larger than an antiparticle. It is also much less massive. Otherwise, it is identical to antimatter if left in a vacuum.