tion:Examples of Chemical ChangesA new compound (PRODUCT) results from a chemical change as the atoms rearrange themselves to form new chemical bonds.Burning woodSouring milkMixing acid and baseDigesting foodCooking an eggHeating sugar to form caramelBaking a cakeRusting of ironExamples of Physical ChangesNo new chemical species forms in a physical change. Changing the state of a pure substance between solid, liquid, and gas phases of matter are all physical changes since the identity of the matter does not change.Crumpling a sheet of aluminum foilMelting an ice cubeCasting silver in a moldBreaking a bottleBoiling waterEvaporating alcoholShredding paperSublimation of dry ice into CARBON dioxide vapor.How to Tell Whether It's a Physical or Chemical Change?Look for an indication that a chemical change occurred. Chemical reactions release or absorb heat or other energy or may produce a gas, ODOR, color or SOUND. If you don't see any of these indications, a physical change likely occurred. Be aware a physical change may produce a dramatic change in the appearance of a substance. This doesn't mean a chemical reaction occurred.In some cases, it may be hard to tell whether a chemical or physical change occurred. For example, when you dissolve sugar in water, a physical change occurs. The form of the sugar changes, but it remains the same chemically (sucrose molecules). However, when you dissolve the salt in water the salt dissociates into its ions (from NaCl into Na+ and Cl-) so a chemical change occurs. In both cases, a WHITE solid dissolves into a clear liquid and in both cases, you can recover the starting material by removing the water, yet the processes are not the same.