Microwaves have wavelengths approximately in the range of 30 cm (frequency = 1 GHz) to 1 mm (300 GHz).
However, the boundaries between far infrared light, terahertz radiation, microwaves, and ultra-high-frequency radio waves are fairly arbitrary and are used variously between different fields of study.
A microwave oven works by passing microwave radiation, usually at a frequency of 2450 MHz (a wavelength of 12.24 cm), through the food.
Water, fat, and sugar molecules in the food absorb energy from the microwave beam in a process called dielectric heating.
Many molecules (such as those of water) are electric dipoles, meaning that they have a positive charge at one end and a negative charge at the other, and therefore rotate as they try to align themselves with the alternating electric field induced by the microwave beam.
This molecular movement creates heat as the rotating molecules hit other molecules and put them into motion.
Microwave heating is most efficient on liquid water, and much less so on fats and sugars (which have less molecular dipole moment), and frozen water (where the molecules are not free to rotate)..
The information provided was found from the websited (http://www.sciencedaily.com/articles/matter_energy/physics/)
"As stated in the above article I've learned that microwaves are electromagnetic waves. Electromagnetic waves are waves that do not require a medium to go through. Microwaves are very good at transmitting information from one place to another. This is one used of microwaves. Another used microwaves have are that shorter microwaves are used in remote sensing. An example of this is weather forecasting. The most commom used of microwaves are those of microwave ovens or the kitchen appliance microwaves. The microwave radiation heats the water molecules within food. This results in the heating of your food but not completely baking your food. One interesting fact about microwaves were that they were first discovered in the 1940's."
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