* No new substances are formed: When salt dissolves, the sodium (Na+) and chloride (Cl-) ions that make up the salt crystal simply separate and become surrounded by water molecules. The chemical composition of the salt and water remains the same.
* The change is reversible: You can recover the original salt by evaporating the water. The salt ions will come back together and form crystals again.
* It's a change in state: The salt changes from a solid state to a dissolved state, but its chemical identity remains the same.
Here's a simplified explanation:
Imagine salt crystals as tiny building blocks. When you put them in water, the water molecules pull the building blocks apart. The building blocks are still the same, but they are now spread out and surrounded by water. This is a physical change because the building blocks (salt molecules) haven't changed, just their arrangement.
In contrast to a chemical change:
A chemical change would involve the salt reacting with water to form a completely new substance, like a gas or a different compound. This wouldn't be reversible just by evaporating the water.
