However, the gaps between the ground and excited states of a molecule are more complicated than the electronic transitions in an atom, as as a molecule will have not only electronic but also vibrational and rotational sub-levels. In other words, a molecule is composed of two or more atoms, each with their own electronic states, which rotate and vibrate with respect to each other such that the energy stored in the molecule is a sum of electronic, rotational and vibrational energy.
As was also the case with an atom, it is possible for a photon to interact with a molecule and scatter from it, with no need for the photon to have an energy which matches the difference between two energy levels of the molecule. Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. It only takes a minute to sign up. Connect and share knowledge within a single location that is structured and easy to search.
As far as I know, scattering occurs when light excites the atoms or molecules to their higher energy state virtual state for scattering followed by emitting photons corresponding to energy differences. I think this process is not quite different with usual absorption and following emission process. What can be the difference btw them? When there is spontaneous emission like in your case , the electron relaxes, emitting a photon.
Before that, the electron needs to be excited, by another photon, that is absorption. So the answer to your question is that scattering is when the photon interacts with the atom, and it can lead to elastic scattering, inelastic scattering or absorption. You have diffused scattering. Diffused scattering is just what happens when light goes off a white surface, and light rays come in and they bounce off in all directions equally. The appearance of the surface is just white. You also have the phenomenon of reflection.
And in reflection, you have a much more uniform kind of scattering. You find, in this case, the light bounces off quite regularly—a reflection off a mirror. And then you have a third kind of scattering called diffraction. Diffraction is a very special kind of scattering in which light waves are split up.
You may have seen the kind of refraction effects you get off a CD when you see that rainbow of colors. Light is being broken up into its component colors by this process.
Iridescence is the process of diffraction. The conservation of energy requires that the energy of electromagnetic energy of radiation hitting a material has to be equal to the energy that is transmitted, absorbed, and scattered. For example, if you shine a light through colored water, you have some transmission, you have some scattering, and you have some absorption.
All three processes are occurring simultaneously. For humans, it is the visible spectrum that interacts with our eyes. Light reflected and scattered by the world around us interacts with our eyes, and that is how we see things around us. The three ways in which electromagnetic waves interact with matter are transmission, absorption, and scattering.
The Electromagnetic Spectrum. Demonstration: Observing the spectra from a variety of light sources. Misconceptions Light, Sound and Waves Many students have an understanding of how coloured filters work, some believe they change the nature of the light in some way Number of Resources 2 Number of References 1 Number of Diagnostic Resources 8.
Some students confuse the primary colours taught in art with the primary colours of light Number of Resources 2 Number of References 1 Number of Diagnostic Resources 4.
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