Polarization of an Atom

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 Computational Model

https://www.youtube.com/watch?v=p_ubxdTOV34

Examples

Be sure to show all steps in your solution and include diagrams whenever possible

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

Put this idea in historical context. Give the reader the Who, What, When, Where, and Why.

See also

Are there related topics or categories in this wiki resource for the curious reader to explore? How does this topic fit into that context?

Further reading

Books, Articles or other print media on this topic

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://ocw.mit.edu/resources/res-6-001-electromagnetic-fields-and-energy-spring-2008/chapter-6/06.pdf

http://www.hho4free.com/electrical_polarization.htm

References

https://www.webassign.net/ebooks/mi4/toc.html?page=14.3