Final answer:
Burning gasoline in an engine is not a physical change but a chemical change, as new substances are formed and the chemical composition of gasoline is altered.
Step-by-step explanation:
Identifying Chemical and Physical Changes
Among the options provided, the process that is not a physical change is burning gasoline in an engine. This is because when gasoline burns, it undergoes a chemical reaction with oxygen in the air to form new substances like carbon dioxide and water vapor. The composition and chemical properties of the gasoline change, which is a hallmark of a chemical change.
- Dissolving sugar in water is a physical change as the chemical structure of the sugar molecules does not change, and they can be recovered by evaporating the water.
- Evaporating sea water to get salt is also a physical change because it involves the phase change from liquid to gas, leaving the salt behind.
- Slicing a piece of bread is a physical change because it changes the shape of the bread but not its chemical composition.