Question

what do these two changes have in common? a piece of pizza rotting in a trashcan roasting a marshmallow over a campfire select all that apply. both are only physical changes. both are caused by heating. both are caused by cooling. both are chemical changes.

Explanation:

Roasting a marshmallow over a campfire involves a chemical change as the heat causes the sugars in the marshmallow to caramelize and new substances are formed. A piece of pizza rotting in a trash - can is also a chemical change because decomposition by bacteria and other microorganisms leads to the formation of new substances. Neither is a physical change, and they are not caused by cooling.

Answer:

Both are chemical changes.