What state of matter is characterized by having a definite volume but no definite shape?

The state of matter characterized by having a definite volume but no definite shape is liquid. In liquids, the particles are closely packed together but can move past one another, allowing the liquid to flow and take the shape of its container. This molecular arrangement enables liquids to maintain a constant volume regardless of the shape of the container they occupy.

Solids, on the other hand, have both a definite volume and a definite shape due to the tightly packed arrangement of their particles, which do not move freely. Gases have neither a definite volume nor a definite shape; they expand to fill their container. Plasma, while less common, consists of highly energized particles and also does not have a definite shape or volume, as it behaves similarly to gases under certain conditions. Thus, liquids uniquely meet the criteria of having a definite volume while taking the shape of their containers.