[kapital]

What is electromagnetism?
(I hope the question is not too general)

[McCoy]

Are you serious?

[kapital]

yes, why?

[McCoy]

yes, why?

No offense, but I thought it was obvious from high school physics.

[kapital]

Then I am sorry for my inappropriate question.

[Ubermensche2012]

Light that moves at a speed relative to the medium in which it travels in. magnetic and electric waves for example move at light speed for example. and so do gamma and infrared through a "vacuum".

[Juan R.]

What is electromagnetism?
(I hope the question is not too general)

Electromagnetism is one of the four fundamental interactions of nature, and the most important for chemists because is the main interaction for usual matter {#}.

The branch of physics studying it (from a classical point of view) is usually also called electromagnetism, but I prefer the terms electrodynamics and electrostatics.

The branch of chemistry that studies the relation between chemical matter and electromagnetism is electrochemistry.

{#} Some chemists study the role of other interactions, for instance the role of the weak interaction (a kind of nuclear interaction) in chiral molecules.

[FreeTheBee]

The branch of chemistry that studies the relation between chemical matter and electromagnetism is electrochemistry.

When talking about interaction of matter and electromagnetism I think more of spectroscopy (IR, UV-VIS, Raman), xray diffraction, light scattering and so... In common electrochemical experiments there is little electromagnetism involved, with the exception of photoelectrochemistry of course.

[Juan R.]

The branch of chemistry that studies the relation between chemical matter and electromagnetism is electrochemistry.

When talking about interaction of matter and electromagnetism I think more of spectroscopy (IR, UV-VIS, Raman), xray diffraction, light scattering and so... In common electrochemical experiments there is little electromagnetism involved, with the exception of photoelectrochemistry of course.

Spectroscopy is the branch that studies the relation between matter and radiation. That radiation does not need to be of electromagnetic origin (EMR).

In electrochemistry we study the relation with electromagnetism; i.e., the relation with charges, currents, electromagnetic fields, etc. Take for instance the electrochemical potential

mu_E = mu + (z F Phi)

where mu is the chemical potential, z is charge, F is Faraday constant and Phi is the scalar potential associated to a electromagnetic field.

The IUPAC defines photoelectrochemistry as "the chemistry resulting from the interaction of light with electrochemical systems."

[tamim83]

According to "Chemi Cool", electrochemistry is the "study of chemical changes produced by electrical current and the production of electricity by chemical reactions"  This seems to be the definition most chemists go with, including myself.  

Also, the only other radiation I can think of is that which would come from radioactivity (alpha and beta radiation for example).  However, these are streams matter (which could have "wave-like" properties according to quantum mechanics) and would not interact with others atoms and molecules in the same way electromagnetic radiation (light) does.  Therefore, I would not classify these interactions with spectroscopy,nuclear chemistry may be more appropriate.

[FreeTheBee]

Spectroscopy is the branch that studies the relation between matter and radiation. That radiation does not need to be of electromagnetic origin (EMR).

I know, therefore I mentioned some examples of techniques that do depend on the interaction between matter and electromagnetic radiation.

In electrochemistry we study the relation with electromagnetism; i.e., the relation with charges, currents, electromagnetic fields, etc. Take for instance the electrochemical potential

mu_E = mu + (z F Phi)

where mu is the chemical potential, z is charge, F is Faraday constant and Phi is the scalar potential associated to a electromagnetic field.

The phi here is the local electrostatic potential.

In principle electromagnetism is involved when charges are moving and thus also in an electrochemical cell, but these effects are normally not taken into account. I wouldn't be surprised if there are people working on this, but it is not part of everyday electrochemistry.

The IUPAC defines photoelectrochemistry as "the chemistry resulting from the interaction of light with electrochemical systems."

Hence, it is a branch of electrochemistry that deals with emr.

Before, (or just after ) going too far off topic, I'll leave it at this.

[Juan R.]

According to "Chemi Cool", electrochemistry is the "study of chemical changes produced by electrical current and the production of electricity by chemical reactions"  This seems to be the definition most chemists go with, including myself.  

Also, the only other radiation I can think of is that which would come from radioactivity (alpha and beta radiation for example).  However, these are streams matter (which could have "wave-like" properties according to quantum mechanics) and would not interact with others atoms and molecules in the same way electromagnetic radiation (light) does.  Therefore, I would not classify these interactions with spectroscopy,nuclear chemistry may be more appropriate.

I do not agree with that narrow definition, neither Brett and Brett do in their Modern Electrochemistry. In their volume 1, they give a more general definition (more general than mine of above also  ) as the study of chemical phenomena associated to separation of charges.

Regarding non-electromagnetic radiation I was thinking on the modern field of ultrasonic spectroscopy and similar.

[Juan R.]

In electrochemistry we study the relation with electromagnetism; i.e., the relation with charges, currents, electromagnetic fields, etc. Take for instance the electrochemical potential

mu_E = mu + (z F Phi)

where mu is the chemical potential, z is charge, F is Faraday constant and Phi is the scalar potential associated to a electromagnetic field.

The phi here is the local electrostatic potential.

In principle electromagnetism is involved when charges are moving and thus also in an electrochemical cell, but these effects are normally not taken into account. I wouldn't be surprised if there are people working on this, but it is not part of everyday electrochemistry.

phi does not need to be an electrostatic potential. Also I emphasized that it is the scalar potential to differentiate it from the vector potential A.

Electromagnetism is also involved when charges are not moving (in this case all electromagnetic phenomena are purely electrostatic). Moreover, it seems that you think that electrochemistry only deals with stationary charges, but "everyday electrochemistry" also deals with currents and the effects than arise from those currents. sometimes this is called nonequilibrium electrochemistry or dynamic electrochemistry.