Magnetic field

[Highschoolsci187]

I wasn't realy sure were to put this but im a highschool student learning about magnetic fields and the more i learn about anything in science the more questions i have in general but this one is particularly bothering me, ok so what i have learned is that a magnetic field is the electrons loosly circling around an object so if thats true then when you hold a magnet about lets say an inch away then the electrons from both fields are touching around a half inch away(just an example im sure that the mesurment of how far the the field on either object is conditional) im just confused because i thought it was all packed so tight that it would be a smaller distance.

also i have a theory but google isn't helping me out much with this the only think i can think of is that there are microscopic pieces of the magnet and the object around them that are bumping into eachother because i was thinking about when you smell something thats microscopic pieces of something touching the back of your toung and if you can have pieciece of that without visualy taking away from the whole that it might be the same concept but i was hoping for a second opinion or someone who actualy knows to assure this or lead me to the right direction

[studiot]

Hello, you have posted this in homework help, but you don't seem to have a homework question.

 

Are you really asking for a better explanation of magnetism or do you have an associated question.

 

Please clarify.

[Highschoolsci187]

im looking for a better explination i supose, this is the main question i have and since its so specific it seemed appropriate to place it here i didnt take much time to look through all the catagories becuse im eager to know.

[studiot]

You are correct that the origin of magnetism in material matter arises from the motion of its electrons.

 

This is because electrons carry an electric charge.

Any moving electric charge generates a magnetic field, and the electrons are always in motion.

 

The electric current in a copper wire is due to electrons in motion and this also generates a magnetic field due to this, however not all material objects carry electric current and yet respond to magnetic fields and some actually produce their own field.

 

Except for ferromagnetic materials (Iron, nickel and a few other substances) no substance exhibits magnetic effects unless it is situated in an externally generated field.

 

Ferromagnetic materials can form what are known as permanent magnets. That is they remain 'magnetised' when there is no external magnetic field. So they can generate a magnetic field in their own right. Copper is not a ferromagnetic material and cannot do this.

 

The magnetic effect in copper wires is due to electrons that are 'free'. That is they are not part of any particular atom and move along the wire, whilst (obviously) the copper atoms stay in place.

 

Electrons belonging to particular atoms are very important since not only do they determine the chemical properties of that atom, they also determine its magnetic properties.

 

The electrons in an atom are circling round the nucleus of the atom in quite specific manner, not "loosely round an object". Because they are travelling in orbit around the nucleus they generate a (small) magnetic field.

 

In the atoms of many substances there are as many electrons going one way as there are going the other so the effects cancel out and there is no net magnetic field.

 

However in iron atoms there are four electrons more going one way than there are going the other around the iron nucleus so these four electrons generate quite a powerful net magnetic field.

 

Finally some atoms have one or two unbalanced electrons orbiting, but the atoms are arranged randomly so that the fields of one atom cancel the fileds of nearby atoms with a net zero result.

 

How are we doing so far?

[EdEarl]

There are good lessons about physics, including magnetism on khanacademy.org, for magnetism see: https://www.khanacademy.org/science/physics/electricity-and-magnetism/v/introduction-to-magnetism

 

This particular lesson is in the middle of the physics lesson, and you might need to start with previous lessons, depending no your current knowledge.

Edited February 13, 2014 by EdEarl