SCIENCE EASY No. 180
Author: Maria Cristina Chaler.
Series Juguemos to why?
Why microwave cooking?
White light is composed of a cluster of energy, some more powerful than others, depending on their frequency (number of waves per second). The higher the frequency the wave energy and consequently more penetrating.
to an electromagnetic wave propagates in space, we can think of as a continuum of peaks and valleys, the wavelength is the distance between peak and peak / off-peak and valley, and longer wavelengths, less frequently, ie, fewer waves pass in one second.
Within the spectrum of white light visible colors are occupying a small space with minimum energy differences among themselves to each other, the blue is more energetic than red. Below the red, infrared rays are invisible but detected with the sense of touch, the feeling of heat produced by above the violet, ultra violet, high energy, also invisible to our eyes, we can not grasp the sense of touch, but our biological body receives and transforms the substance beneath the skin into vitamin D resulting in the brown color so characteristic of exposure to sunlight.
Where are the microwaves within this spectrum?
L as microwaves are low frequency waves that are located below the infrared over radio waves are not very penetrating but enough for a man has found an advanced technology that allows use in daily life and apply them to cook food from the inside as opposed to the traditional oven that cooks from the outside through the infrared rays released by the fire.
Let the core of why
Food has within it a large percentage of water molecules formed by an oxygen atom and two hydrogen atoms (H2O) , which in turn are characterized by an asymmetric electron cloud, caught in the area of \u200b\u200bthe atom oxygen (negative area) rather than the hydrogen (positive area), so it is said to be a molecule with permanent dipole, which causes it to behave in front of a magnetic field as a small magnet and its poles east the opposite pole of the field. As microwaves are able to penetrate the material, its entry generates magnetic fields that cause the water molecules are oriented according to their electrical charges, not static but constantly turning movements. Giran 2, 45 million times a second and this turn generates heat, as any movement of matter, which is transmitted the rest of the substance. Any other molecule that is polar and is present in the food vibrate as the water and help to warm up. As there are millions and millions of molecules vibrating cooking will be much faster than a regular oven where the heat waves (infrared) do not penetrate matter and cooking from the outside in and slowly.
Foods in the regular oven will brown the outside because it dries in the microwave instead, as cooking takes place from within and are not as steamed brown.
Any substance inside holds heat polar molecules by the passage of microwaves substances with little water or polar molecules that do not have inside will not be heated, only warm.
The famous browning dish is made of a material that can be heated by the action of the microwaves and to make contact with dry food and brown surface.
Metals are capable of reflecting the waves, for that reason many microwaves have metal walls to encourage reflection and distribution of the same and the glass front of the device has a metal mesh to prevent the microwaves go abroad. ;
wave generator is called a magnetron, the device emits a piercing through which we can observe in one of the walls of the apparatus, excess metal in the furnace, it is undesirable because if the waves are reflected back to the magnetron too and they burn .
Microwaves electrons to move along the metal when it is pointed, accumulate in them and can escape in the form of sparks that come to burn any flammable substance of the food, it is not advisable to place objects ; metal in the microwave especially those that have sharp points or edges where electricity sparking escape.
And now ... A microwave cooking knowing what it is!
Man is just a dot on the vast Universal but has an important purpose of being 
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