Dissolving salt in water is considered a physical change because there’s only a change in the state of matter but no change in the chemical composition of matter. Bear in mind that physical change is defined as a change affecting the form of a chemical substance, but not it's the chemical composition. Dissolving salt in water is a typical example of a physical change. Also, remember that physical change can be reversible, but the chemical change is irreversible.
Heating the water and allowing it to evaporate will change the salt back to its solid-state water will be in its gaseous state. Dissolving salt in water also has a chemical reaction part to it. The ionic bonds in salt are much weaker than the covalent bonds of water, so water molecules break the bond between sodium and chloride ions, and this breakdown the bond that holds them together.
The main reason why this is still considered as physical change is due to the fact that only the state of the matter has changed. This means that if ever there is a process that will be done like condensation to the salt solution, the water will evaporate and the salt will be left behind. This explains why this is still considered to be a physical change.
A chemical change occurs when the element will not be able to go back to its original state anymore. For example, the digestion of food is considered to be a chemical change. The nutrients from food will be absorbed by the body, and the rest of the food or the excess food will turn to waste. When the food is removed from the body, it does not resemble the food that we have eaten any more.
Salt dissolving into water is a physical change because the chemical makeup doesn't change. Salt is a household staple, used for many purposes. One of the most common purposes is adding it to boiling water, especially when making pasta. The salt would be added to the person's taste. When salt is added, the salt dissolves. When this occurs, new bonds are formed between salt and water.
There is so much energy that the relationship between the salt molecules and the water molecules are broken. This process also occurs when sugar is added to water. However, if the ratio of the salt and water outweighs the ration to water, some will not dissolve.