An example of a chemical change is Mashing potatoes
Dew disappearing from the grass
Frying a hamburger
A magnet sticking to the refrigerator

Frying a hamburger

Explanation:

when frying a hamburger you change the properties of the meat by applying heat and in the other answer choices the element is not changed.

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.