Final answer:
Matter is anything that occupies space and has mass. Solids, liquids, and gases are all forms of matter. Mass is a measure of the amount of material within an object, while volume is the measure of the physical space it occupies.
Step-by-step explanation:
Matter is defined as anything that occupies space and has mass. Solids and liquids are more obviously matter: We can see that they take up space, and their weight tells us that they have mass. Gases are also matter; if gases did not take up space, a balloon would not inflate (increase its volume) when filled with gas.
Mass is a measure of the amount of material within an object. The quantity or amount of matter in an object is determined by the numbers of atoms and molecules of various types it contains.
The volume of an object is the measure of the physical space it occupies. Volume is measured in cubic units, such as cubic centimeters or liters. The volume is the "size" of an object.