What are the properties of plasma?
Answers
Plasma is overwhemingly the dominant constituent of the universe as a whole. Yet most people are ignorant of plasmas. In daily life on the surface of planet Earth, perhaps the plasma to which people are most commonly exposed is the one that produces the cool efficient glow from fluorescent lights. Neither solid, nor liquid, nor gas, a plasma most closely resembles the latter, but unlike gases whose components are electrically neutral, plasma is composed of the building blocks of all matter: electrically charged particles at high energy.
Plasma is so energetic or "hot" that in space it consists soley of ions and electrons. It is only when plasma is cooled that the atoms or molecules that are so predominant in forming gases, liquids, and solids that we are so accustomed to on Earth, is possible. So, in space, plasma remains electrically charged. Thus plasmas carry electric currents and are more influenced by electromagnetic forces than by gravitational forces. Outside the Earth's atmosphere, the dominant form of matter is plasma, and "empty" space has been found to be quite "alive" with a constant flow of plasma.
Plasma is by far the most common form of matter known. Plasma in the stars and in the tenuous space between them make up over 99% of the visible universe and perhaps most of that which is not visible. On earth we live upon an island of "ordinary" matter. The different states of matter found on earth are solid, liquid, and gas. We have learned to work, play, and rest using these states of matter. Sir William Crookes, an English physicist, identified another, more fundamental, state of matter in 1879. In 1929, Nobel Laureate Irving Langmuir gave this state a name, plasma. He borrowed the term from medical science because the matter with which he worked resembled life itself. It formed cells through bifurcation and often acted in a complicated and unpredictable manner. Plasma is defined as an assemblage of charged particles called electrons and ions that react collectively to forces exerted by electric and magnetic fields.
Like gases, plasmas have no fixed shape or volume, and are less dense than solids or liquids. But unlike ordinary gases, plasmas are made up of atoms in which some or all of the electrons have been stripped away and positively charged nuclei, called ions, roam freely.