"Anhydrous copper sulfate turns blue when it meets water" is a chemical change process. This is because in this process, anhydrous copper sulfate (CuSO₄) reacts chemically with water molecules to generate a new substance - copper sulfate pentahydrate (CuSO₄·5H₂O). Copper sulfate pentahydrate is a blue crystal, which has a significant color difference from the white or off-white powder of anhydrous copper sulfate.

The definition of a chemical change is a change in which a new substance is generated. In this example, anhydrous copper sulfate and water, as reactants, generate a new substance, copper sulfate pentahydrate, through a chemical reaction. Therefore, this change meets the definition of a chemical change.

In addition, this change is accompanied by some physical phenomena, such as dissolution and crystallization. However, these physical phenomena are only part of the chemical change process and cannot be used alone as a basis for judging whether it is a chemical change.

In summary, "anhydrous copper sulfate turns blue when it meets water" is a chemical change process because it involves the generation of new substances.