Crushing is considered a physical property. When you crush a substance, such as a piece of chalk or a can, you are altering its size and physical form, but you are not changing its chemical composition. For example, when you crush a rock, the minerals that make up the rock remain the same; they are just in smaller pieces.
In contrast, a chemical property involves a change in the substance’s chemical makeup. For instance, when iron reacts with oxygen to form rust, a new substance is created. This is a chemical change, and it involves a transformation of the original material.
In summary, crushing does not change what the material is; it only affects its physical form. Therefore, it is classified as a physical property.