Answer
(a) physical
(b) chemical
(c) physical
(d) chemical
Work Step by Step
(a) physical
This is an example of a physical change because there is no chemical reaction occurring.
(b) chemical
This is an example of a chemical change because when a firecracker explodes, a chemical change is occurring such that the chemical change causes an explosion.
(c) physical
This is an example of a physical change because magnetizing something just means that the atoms are being realigned in the iron nail, but the substance making up the iron nail has not changed.
(d) chemical
This is an example of a chemical change because when a cake is baking, the baking soda inside the cake is being changed into carbon dioxide, which causes the cake to rise.
