Question

mowing the lawn *
chemical change
physical change
corroding metal *
chemical change
physical change
bleaching your hair *
chemical change
physical change

Explanation:

1. Mowing the lawn only changes the shape and size of the grass, without forming new substances, so it is a physical change.
2. Corroding metal involves a chemical reaction between the metal and substances in the environment (such as oxygen and water), forming new substances like metal - oxides, so it is a chemical change.
3. Bleaching hair uses chemicals to react with the pigments in the hair, changing their chemical structure, so it is a chemical change.

Answer:

1. mowing the lawn: physical change
2. corroding metal: chemical change
3. bleaching your hair: chemical change