Physical change 1. No new objects are created. 2. The physical nature of the object changes. 3. The molecular structure of an object does not change. 4. The chemical attachment of the object does not change. 5. Physical change is temporary. When the cause of general change (e.g. , heat and pressure) is removed, the object returns to its previous state. . Absorption or emission of heat energy may or may not occur. Chemical changes 1. One or more new types of objects are created. 2. The physical and chemical properties of objects change. 3. By changing the molecular structure of an object , a completely new molecule is formed. 4. The chemical attachment changes. 5. This change is permanent. The object cannot be easily restored to its former state. . Absorption or emission of heat energy must occur.