Chemical changes occur when substances transform into new substances with different properties. This process involves the breaking and forming of chemical bonds, resulting in a change in the composition of the material. Common examples include rusting of iron, burning of wood, and the reaction between vinegar and baking soda. During a chemical change, indicators such as color change, gas production, or temperature change may be observed. These changes are often irreversible, meaning the original substances cannot be easily recovered. Understanding chemical changes is essential in fields like chemistry, biology, and environmental science.