chemical and phisical changes
Search Res is any change that results in the formation of new chemical substances. At the molecular level, changes involves making or breaking of bonds between atoms. These chemical are chemical iron rusting (iron oxide forms) gasoline burning (water vapor and carbon dioxide form)
There are several differences between a physical and chemical change in matter or substances. A physical change in a substance doesn't change what the substance is. In a chemical change where there is a chemical reaction, a new substance is formed and energy is either given off or absorbed.