What are the three common states of matter?

Correct answer: Solid liquid and gas

The direct answer is A: solid, liquid and gas are the three common states of matter. Matter is anything that has mass and occupies space. In a solid, particles are closely packed and the substance usually has a fixed shape and volume. In a liquid, particles can move past one another, so the liquid has a fixed volume but takes the shape of its container. In a gas, particles are far apart, so it has neither a fixed shape nor a fixed volume. Option A gives these physical states and is correct. Option B lists forms of energy or physical phenomena, not states of matter. Option C lists properties detected by the senses, not states. Option D classifies elements or substances as metals, non-metals and metalloids; that is a different classification based on chemical properties. A substance can change from one state to another when temperature or pressure changes. Memory cue: solid keeps shape, liquid flows, gas fills space.