Consider melting ice cream. when it melts, it takes heat away from the environment and so the reaction is endothermic. when you freeze ice cream, the heat is being removed from what?

Hi!

First of all, the melting of ice cream is not a chemical reaction, because there is no change in the components of the ice cream and if you freeze the ice cream again, you will get the same ice cream that you had previously.

The melting of ice cream is an example of a physical change, in which a substance goes from solid to liquid state, and it is an endothermic physical change.

When you freeze ice cream, the heat is removed from the ice cream, making it an exothermic process, when heat is liberated to the environment and it's taken away from the substance, in this case, the ice cream.