* Chemical Properties: Describe how a substance reacts with other substances. They involve changes in the chemical composition of the substance.

* Physical Properties: Can be observed without changing the chemical composition of the substance. They include things like color, density, melting point, etc.

When you neutralize a base, you are reacting it with an acid. This reaction changes the chemical composition of both the acid and the base, resulting in the formation of salt and water.

Example: Neutralizing sodium hydroxide (NaOH, a base) with hydrochloric acid (HCl, an acid) results in the formation of sodium chloride (NaCl, salt) and water (H₂O).

Chemical Equation:

NaOH + HCl → NaCl + H₂O

This chemical change is what defines neutralization as a chemical property.