Which of the following results in a chemical change in matter building a strong braiding hair or boiling water or Burning wood

Chemical reaction is something that the matter will change completely. if you un braid your hair didn't change or if you cool the water vapor its going to be liquid again but no way you can make the burning wood to its original state which means thats the chemical reaction

Burning wood because once it is burned, you cannot change it back. Boiling water can be taken back to the form that it started at, and the same goes for hair.