* No new substances are formed: When salt dissolves, the sodium (Na+) and chloride (Cl-) ions separate and become surrounded by water molecules. The chemical composition of the salt remains the same (NaCl), it's just dispersed in the water.
* The change is reversible: You can easily recover the salt by evaporating the water.
* No chemical bonds are broken or formed: The ionic bonds holding the sodium and chloride ions together in the salt crystal are not broken during dissolving. The water molecules simply surround the ions and pull them apart.
In contrast, a chemical change would involve:
* The formation of new substances with different chemical compositions.
* The breaking and forming of chemical bonds.
* The change being irreversible or very difficult to reverse.
