Is burning paper a physical or chemical reaction?
Let's start of by understanding the difference between a physical and chemical reaction.
A physical reaction occurs when the physical state of the substance remains the same despite what has happen to it. For instance, the tearing of paper is physical as it's still paper even when you tear it.
A chemical reaction is when the substance is chemically change. a chemical reaction also can't be reversed.
When paper is burn, the cellulose in the air reacts with the oxygen to form carbon dioxide and water. Also, the action of burning paper can't be reversed.