A physical change is a change in the form or appearance of a substance, without a change in its chemical composition. In this case, the salt dissolves into the water, forming a homogeneous mixture called a solution. The salt molecules disperse throughout the water, but they retain their chemical identity and composition.

Some indicators of a physical change are :

- No new substance is formed

- The starting materials can be reformed from the product

- There is usually a change in physical properties, such as color, shape, or state of matter