Dissolving common salt in water is a physical change because the process can be reversed. If we boil the salt water solution, the water will evaporate, and the salt can be obtained. The evaporated water can be condensed to liquid form again. Thus dissolving common salt in water is a physical change in which just the state of compound changes and no chemical reactions occur.
FINAL ANSWER-
Hence, dissolving a common salt is a physical change.