Chemical properties are those that describe a substance's tendency to undergo a particular chemical reaction. They are usually just observable in the process of a chemical reaction, therefore a chemical property can only be established by changing a substance's chemical identity. Some examples are flammability, tendency to oxidize (corrode), tendency to react with acid or base, and tendency to chemically decompose at high temperatures (chemical stability or lack thereof.) Some thermodynamic quantities, such as heat of formation and heat of combustion, are also chemical properties.
Chemical properties are distinguishable from physical properties in that physical properties are observable independent of a chemical reaction. Examples of physical properties are density, temperature, color, odor, hardness, melting point and boiling point. A physical change may take place during the observation of a physical property, for a phase change, but there is no change in chemical identity of the substance.