What state of matter takes the shape of its container regardless of how much of it is present

Liquids such as water take the shape of their container regardless of the volume present. This is because the particles in a liquid are packed not as tightly as in a solid, or as freely as in a gas. There are gaps between the particles and this allows them to slide over one another and maintain the shape of the container that they are placed in.

Yes it would be a physical change.