Final answer:
Gases undergo changes in volume most easily because they are compressible. This characteristic is due to the high energy and random motion of gas particles
Step-by-step explanation:
The state of matter that undergoes changes in volume most easily is gas. This is because gases are compressible, meaning they can expand or contract to fill the space they are in. This characteristic is due to the high energy and random motion of gas particles, which leads to them being far apart from each other, therefore taking up more volume. In comparison, solids and liquids are incompressible, which means their volume is fixed and does not easily change. Frozen is a state of a substance, typically a term for a solid water (ice), so its volume is not easily changeable as well.
Learn more about States of Matter