What state of matter has a definite shape and volume?

The state of matter that has a definite shape and volume is solid. In solids, the particles are closely packed together in a fixed arrangement, which allows them to maintain a specific structure. This arrangement prevents the particles from moving freely, giving solids their characteristic rigidity. As a result, solids do not conform to the shape of their container, and they maintain their volume regardless of external conditions.

In contrast, gases do not have a definite shape or volume; they expand to fill the shape of their container. Liquids have a definite volume but take the shape of their container, flowing to adjust to its shape. Plasma, which consists of ionized gases with free electrons, does not possess a definite shape or volume either, behaving similarly to gases. Understanding these distinctions clarifies why solid is the only state of matter among the options that maintains both a fixed shape and volume.