Usually it means that something has gone through a physical change and any chemical properties of that substance are not altered.
If you burn something it is a chemical change, however if you melt of boil it, it is a physical change.
lighting is a chemical change
Chemical change
Something that burns or is flammable would be a chemical change.
A physical change is one where just the appearance of something changes and a chemical change is where the genetic makeup of something changes.
If something's reacting, it's a chemical change.
When something reacts, that is a chemical reaction. Chemical change.
When you mix something with something else
When you mix something with something else
Burning wax is a chemical change. If you are burning something, it will always be a chemical change.
Chemical
A decrease in temperature is a physical change, not chemical.