The correct answers are tails of comets, the ionosphere, and a neon sign.
Plasma refers to an ionized gas, and is generally regarded as a discrete phase of matter. In this case ionized signifies that at least one electron has been dissociated from a substantial ratio of the molecules. The tails of comets are primarily formed of plasma. Ice cubes are an example of solid component. A gas fire is an example of gas. The ionosphere is primarily formed of plasma. A neon sign utilizes plasma in order to function, while a flashlight utilizes a light bulb, which is not an example of plasma.
