Plasma (physics)

Plasma is a state of matter that results from one of the other three states (often, the gaseous one) having undergone an appreciable degree of ionization. It thus consists of a significant portion of charged particles (ions and/or electrons). While rarely encountered on Earth, it is estimated that 99.9% of all ordinary matter in the universe is plasma. Stars are almost pure balls of plasma, and plasma dominates the rarefied intracluster medium and intergalactic medium.