change in form of matter but not what it is made of 

the visual disappearance of one substance into another.

Matter that has a definite volume but no definite shape.

matter that has no definite shape or volume

something that has mass and takes up space.

Matter that has a definite volume and holds its own shape.

Something that has no definite shape.

The material that something is made of.

The pull of gravity on matter.