What are the three states of matter commonly recognized?

The three states of matter commonly recognized are solid, liquid, and gas. This classification is fundamental in understanding the physical properties of substances and how they behave under various conditions.

In this context, solid refers to a state of matter characterized by a definite shape and volume, where the particles are closely packed together and vibrate in place. Liquid differs from solid in that it has a definite volume but takes the shape of its container, with particles that are close together but can move past one another. Gas has neither a definite shape nor a definite volume; the particles are far apart and move freely, filling the entire space available to them.

The other options introduce states that, while they exist, are not typically considered the primary states of matter. Plasma, for instance, is often described as the fourth state of matter, but it is less commonly recognized in basic classifications. Vapor typically refers to the gaseous state of a substance that is liquid at room temperature, but it does not constitute a distinct state of matter. Thus, the clear, widely accepted classification remains solid, liquid, and gas.