You are late for school. Pop a toaster cake in the microwave, push some buttons, and within seconds you can have a fast and easy breakfast. Microwave ovens can heat food in seconds and cook meals in minutes. Inside the microwave is a special tube called a magnetron that changes electricity into high-frequency microwaves.
Microwaves are a form of electromagnetic energy. Microwaves cause water and food molecules to vibrate very quickly. This creates a friction that produces heat, which can cook or warm up food fast.
Heating a sponge in a microwave for two minutes can kill the bacteria that can settle on the sponge.
Microwaves can heat the metal to the point where it can cause fire or produce harmful gases.