Burning wood is a chemical change and not a physical change because the carbon reacts with the oxygen, and that creates ash and smoke, you cannot undo ash and smoke, so therefore, it's only a chemical change
Burning of wood is a chemical change as new substances which cannot be changed back (e.g. carbon dioxide) are formed. For example, if wood is burned in a fireplace, there is not wood anymore but ash. ... Physical changes are a change in which no new substances are formed, and the substance which is changed is the same.
