01:160:161 Chapter Notes - Chapter 7.1-7.4: Combustibility And Flammability, Chemical Equation, Nonmetal
Document Summary
In a chemical change, atoms rearrange and the original substances transform into different substances. Gasoline burns in the presence of oxygen. Burning of sugar in a hot pan. Transformation of oxygen and carbon dioxide into glucose (photosynthesis) Matter can also undergo physical changes which do not change its composition. The atoms or molecules that compose a substance do not change their identity during a physical change. Chemical and physical change are manifestations of chemical and physical properties. A chemical property is a property that a substance displays only by changing its composition via a chemical change. A physical property is a property that a substance displays without changing its composition. Only chemical examination can confirm whether any particular change is chemical or physical. Chemical changes are often evidenced by temperature or color changes and occur via chemical reactions. In a combustion reaction, a substance combines with oxygen to form one or more oxygen- containing compounds (water and carbon dioxide)