What are the three primary states of matter?

The three primary states of matter are solid, liquid, and gas. These states are foundational in understanding the physical world around us.

In a solid state, particles are tightly packed together in a fixed arrangement, which gives solids a definite shape and volume. In contrast, liquids have particles that are still close together but can move past one another, allowing liquids to take the shape of their container while maintaining a definite volume. Gases have particles that are far apart and move freely, resulting in no fixed shape or volume, as they will expand to fill any container they occupy.

Plasma is another state of matter, but it is not one of the primary states. It consists of ionized gases with free-moving charged particles, often seen in stars, including the sun. The combination of solid, liquid, and gas encompasses the basic forms that matter can take under standard conditions, making it a fundamental concept in both science and everyday life.

Vapor refers to the gaseous state of a substance that is normally a liquid at room temperature, and energy is not a state of matter but an unrelated concept. Thus, the correct answer focuses on the three fundamental and distinct states that characterize matter.