* Freezing is the opposite of melting. Melting is endothermic (absorbs heat), and freezing is the reverse.
* Heat is released during freezing. When water freezes, the water molecules slow down and become more ordered, forming a crystalline structure. This process releases energy in the form of heat.
Think of it this way: Your freezer needs to remove heat from the water in order to freeze it. That heat is released into the freezer compartment, which is why your freezer gets warm when you make ice.
