Heat

[Shannon_McCauley_2D]

If we have a closed system of a microwave and we heat up soup inside it, why is it that the air inside doesn't heat up and burn our hands like touching the soup bowl would?

[Cliff Danza 3F]

The way microwaves work is by creating an electric field that changes the direction of dipole molecules rapidly, transferring to thermal energy. Most often this works on the water in the moisture of the food. There is water vapor in the air, but the amount being heated is too small to lead to injury.