Polarization of an Atom: Difference between revisions
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<math>{\vec{p} = α\vec{E}}</math> for almost all materials, the dipole moment '''p''' of the polarized atoms or molecules is directly proportional to the magnitude of the applied electric field '''E'''. The constant '''α''' is called the "polarizability" of a particular material. Many of these polarizability values have been measured experimentally and can be found in reference volumes. | <math>{\vec{p} = α\vec{E}}</math> for almost all materials, the dipole moment '''p''' of the polarized atoms or molecules is directly proportional to the magnitude of the applied electric field '''E'''. The constant '''α''' is called the "polarizability" of a particular material. Many of these polarizability values have been measured experimentally and can be found in reference volumes. | ||
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===A Computational Model=== | ===A Computational Model=== | ||
Revision as of 00:34, 3 December 2015
Claimed by Owen Fisher
This page serves to outline and explain the inner workings and hidden mechanisms of the polarization of an atom.
The Main Idea
In an atom, the cloud of electrons, while connected to the nucleus, is not exactly centered on the nucleus. For this reason, atoms can interact with external charges and become polarized. The nucleus and cloud of electrons can move relative to each other. If an external charge comes into the same space that an atom occupies or is close by, the charge creates an electric field, which exerts a force on the atom. "Applied" electric fields such as this explain why the electron cloud and nucleus can move relative to each other. For example, if a positive charge is placed to the left of an atom, an electric field will be created that shifts the electron cloud of the atom towards the positive charge (to the left) and will shift the net positive nucleus away from the charge (to the right) as two objects of the same charge repel each other. In this case, it is now more probable to find an electron to the left of the nucleus, rather than the right.
A Mathematical Model
[math]\displaystyle{ {\vec{F} = q\vec{E}} }[/math] where F is the force created by the electric field E and the charge of a particle q. This force is what causes the atom to become polarized.
[math]\displaystyle{ {\vec{p} = α\vec{E}} }[/math] for almost all materials, the dipole moment p of the polarized atoms or molecules is directly proportional to the magnitude of the applied electric field E. The constant α is called the "polarizability" of a particular material. Many of these polarizability values have been measured experimentally and can be found in reference volumes.
a.jpg)
A Computational Model
Examples
Be sure to show all steps in your solution and include diagrams whenever possible
Simple
Middling
Difficult
Connectedness
How is this topic connected to something that you are interested in?
- Atoms are the composition of all life. Anything can be broken down into atoms and subatomic particles. If we are able to understand atoms we understand the fundamental concepts of all life, and that is pretty interesting in my opinion.
How is it connected to your major?
- Polarization of atoms is not directly related to my major of Mechanical Engineering; however, there are classes I am required to take such as Intro to Physics 2 and Chemistry where the polarization of atoms directly applies.
Is there an interesting industrial application?
- There are many interesting industrial applications of the polarization of atoms over a broad scope of fields.
Some of these include:
Chemistry
- Checking chirality of organic compounds
- Infrared spectroscopy
Astronomy
- Providing information on sources of radiation and scattering, polarization probes the interstellar magnetic field
- Polarization of cosmic microwave background is being used to study the physics of the early universe
3D Movies
- Images are projected from the projector with multiplexed polarization
- 3D glasses with suitable polarized filters ensure that each eye receives only the intended image
Communication and Radar
- All radio transmitting and receiving antennas are intrinsically polarized-think FM and AM radio
- Vertical polarization is used to radiate a radio signal in all directions, such as those used in mobile phones
- Alternating vertical and horizontal polarization allows satellite communication systems to broadcast two separate transmissions on a single frequency
Material Science Engineering
- the relationship between strain and birefringence motivates the use of polarization in characterizing the distribution of stress and strain in prototypes
Navigation
- Sky polarization was used in the 1950s when navigating near the poles of the Earth's magnetic field when neither the sun nor stars were visible
History
The two scientists accredited with first coming up with the electron cloud model of the atom, on which atom polarization is based upon, are Ernest Rutherford, a New Zealand born British scientist, and Niels Bohr, a Danish physicist. Both of these gentlemen's atom models included the electron cloud. Rutherford released his model in 1911, and Bohr came out with his model shortly thereafter in 1913. Rutherford's model however, suggested that all atoms were unstable. Bohr corrected this by suggesting that the electrons in the atom could only have certain classical motions. Without these two men, we could never have discovered how the polarization of an atom works.
See also
Further reading
- Polarization Functions for First and Second Row Atoms in Gaussian type MO-SCF Calculations by B. Roos and P. Siegbahn
- General Contraction of Gaussian Atomic Orbitals: Core, Valence, Polarization, and Diffuse Basis Sets by Richard C. Raffenetti
- Polarization Propagator Methods in Atomic and Molecular Calculations by Jens Oddershede, Poul Jørgensen, and Danny L. Yeager
- Phase of the Atomic Polarization in High-Order Harmonic Generation by Maciej Lewenstein, Pascal Salières, and Anne L’Huillier
External links
http://www.physicsclassroom.com/class/estatics/Lesson-1/Polarization
http://academics.smcvt.edu/abrizard/EM/dielectric_I.pdf
http://budker.berkeley.edu/papers/pdfs/QBvisualisationPreprint.pdf
http://www.hho4free.com/electrical_polarization.htm
References
https://www.webassign.net/ebooks/mi4/toc.html?page=14.3
http://www.slideshare.net/pabitadhungel321/polarization-and-its-application