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Name: Pragya N.
Status: educator
Age: 40s
Location: N/A
Country: N/A
Date: 2001-2002


Question:
How is reflection of an electro-magnetic wave different from refraction at atomic level? How does an atom decide to reflect and / or refract an electro-magnetic wave of a particular frequency?


Replies:
Hi, Pragya !!!

Good question...But, take into consideration that a metal reflects electromagnetic waves because of its free electrons. Non metals have NOT this property, and then comes into action the refraction, although part of it is reflected. The refraction occurs owing to interference between both electromagnetic fields of the material under observation AND the wave electromagnetic field.

Regards

Alcir Grohmann
Beschaffung SAM


Pragya N.

At an atomic level, reflection and refraction are exactly the same. A photon is absorbed, held for a moment, and then the energy is released as another photon, in a fairly random direction. Refraction occurs when many photons released from many atoms in a forward direction interfere constructively, working together to make a beam bright enough to stimulate your eye. Reflection happens when the constructive interference is in the backward direction. Photons in other directions are usually identified as heat emitted in the form of radiation: energy is lost, but not in high enough intensities to stimulate visual instruments.

Dr. Ken Mellendorf
Illinois Central College



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