Microwave

The microwave was invented in 1945 by the American engineer Percy Spencer.

When Percy Spencer was investigating possible ways to improve the functioning of the radar in the Raytheon Company he discovered that  that the rod chocolate carrying in the Pocket was melting while he was in front of a radar.

The microwave uses electromagnetism.

How does the microwave oven work?

The airwaves in this range have the property of being absorbed by the water, fat and sugar molecules. To be absorbed, the waves become directly in the movement of these molecules (That we know as heat) the water molecules are dipolar, and have a positive charge on one side and negative in another. These molecules are trying to align themselves with the fluctuating electric field generated by the waves. However, the direction of the electromagnetic field is reversed 2,500 million times per second by the clashes between the molecules, which are put in motion, dispersing power,what is  as knownheat.

but... be careful!

Although it is a common appliance in all houses can be very dangerous given that may explode!

If you put metal objects, lights or things that have charge of gunpowder as firecrackers or bomblets may explode.