The States You Know

You learned three states of matter in school: solid, liquid, and gas. Heat a solid and it melts into liquid; heat the liquid and it boils into gas. But heating does not stop there.

When a gas gets hot enough, collisions tear electrons loose from their atoms. The result is plasma — a soup of free electrons and positively charged ions. Unlike ordinary gas, plasma conducts electricity, responds to magnetic fields, and glows.