The microwave oven is one of the great inventions of the 20th century - millions of homes in America have one.
Microwave ovens are popular because they cook food incredibly quickly.
They are also extremely efficient in their use of electricity because a microwave oven heats only the food - nothing else. A microwave oven uses microwaves to heat food. Microwaves are radio waves . When they are absorbed they are converted directly into atomic motion - heat. Metal reflects microwaves, which is why metal pans do not work well in a microwave oven.