Answer: Thus chopping a log into sawdust is not an example of a chemical reaction.
Explanation:
Physical reaction is a reaction in which there is no rearrangement of atoms and thus no new substance is formed. There is only change in physical state of the substance.
Example: chopping a log into sawdust as the shape and size of wood changes.
Chemical reaction is a reaction in which there is rearrangement of atoms and thus new substance is formed. There may or may not be a change in physical state.
Example: burning a plastic water bottle : as the plastic would combine with oxygen to give oxidised products.
the production of hydrogen gas from water: the chemical composition changes
the tarnishing of a copper penny: oxidation of copper takes place to give copper oxide.
charging a cellular phone: the electrical energy is used for a chemical reaction