a. physical change, it is reverse reversible since no new substance is created.
b.chemical change, The iron reacts with water and oxygen to form hydrated iron(III) oxide, which we see as rust.
c. chemical change, Bananas contain compounds known as polyphenol oxidases and iron-containing chemicals. These chemicals react with oxygen to turn the fruit brown.
d. physical change, there is no new substance created, and there is no change in the original composition of wood.