* No new substances are formed: When sugar dissolves, the sugar molecules are simply dispersed throughout the water. They don't change their chemical composition. You could evaporate the water and recover the sugar crystals, essentially the same as the original sugar cube.
* Change is reversible: The process of dissolving is easily reversed by evaporating the water.
* No chemical bonds are broken or formed: The sugar molecules remain intact. They simply separate and become surrounded by water molecules.
Key takeaway: Physical changes alter the form or appearance of a substance but don't change its chemical composition. Chemical changes result in the formation of new substances with different properties.
