Part 4/6:
From Electromagnetic Waves to Heat: The Role of Water Molecules
The microwaves generated within the magnetron are channeled into the oven chamber through an antenna and a wave guide. These waves bounce off the metal interior of the microwave, evenly distributing energy throughout the space.
What makes microwaves effective at heating food is their interaction with water molecules. Inside food, water molecules are polarized—having a positive end and a negative end. When exposed to the oscillating electromagnetic field of microwaves, water molecules attempt to align with the changing electric field. Since the microwave frequency is tuned precisely for this purpose, the molecules flip back and forth rapidly.