What coexist in plasma?

Plasma is often referred to as the fourth state of matter and is characterized by a collection of charged particles. In plasma, both ions (which are atoms that have lost or gained electrons) and free electrons coexist. This unique environment enables the creation of electric and magnetic fields, making plasma highly conductive.

The presence of ions and electrons in plasma allows for various physical phenomena, such as lightning and the operation of fluorescent lights. The high temperature of plasma provides sufficient energy to strip electrons from atoms, forming ions and leading to a mixture of positively charged ions and negatively charged electrons.

Understanding that neutrons do not typically exist freely outside of atomic nuclei, and that molecules and solid particles do not coexist as such in a plasma state, helps clarify why the coexistence of ions and electrons is the defining characteristic of plasma.