why do magnets attract metal?

Answer 1

I've already answered this question and you might want to refer to that for more details. But here goes.

A magnet is made of ferromagnetic materials, and will only attract ferromagnetic materials. These are iron, nickel and cobalt. Any alloy that contains one or more of those is ferromagnetic.

The metal forms tiny grains as it cools from a liquid to a solid, and within these tiny grains are even smaller regions called magnetic domains. Think of groups of atoms packed together. Unless a material is abolutely pure, there will be odd atoms of other elements and when the metal cools, they do not stack together absolutely correctly. If it is only a tiny amount of impurities, we do not notice the difference in terms of size, shape or weight.

But the domains are not lined up the same. Think of a bunch of guys just starting basic training. They are all milling around on the parade ground. But let's say that we heat the bar of metal until it is almost ready to melt and then subect it to a strong magnetic field (stick it inside the coil of a strong electromagnet, and let it cool that way.)

Now they are all lined up the same way (just the way a bunch of paper clips will al line up when you pick them up with a magnet.) And when the metal cools and become solid once more, now they stay in that position. It is like a drill sergeant coming and yelling at the new recruits until they line up in formation. Now they are ready to take orders and get some useful work done.

When the troops all line up and march the same way, you can see the result. They are more orderly, when they march along their feet all hit the ground at once, and they look unstoppable!

It is the same way with the magentic material. Each one of the individual atoms has its own magnetic field, but when they are all pointing in random directions, nothing useful can be done. Some are pointing one way, some the opposite way. They act against each other and their corporate effect cannot be felt.

So, now that the atoms within the domains are lined up together, and the metal has cooled and solidified into a solid bar again, the domains are lined up in formation. Now, they are all pointing in the same direction and we can feel the effects of the magnetic field even outside the magnet itself. The magnetic field reaches beyond the magnet and loops around in space until it reaches the other pole, forming a sort of circuit.

Okay, now we have a magnet and we can understand why it attracts another magnet, because opposite poles attract. north attracts south and south attracts north. (No such thing as gay magnets! it's a law of nature!).

But why does it attract ordinary non-magnetized iron or steel?

That has to do with the fact that even though the metal is solid, and the atoms cannot flow away as in a liquid, the atoms are still free to rotate in place without moving from where they are.

Think of the group of raw recruits before they go through their basic training. They are standing around. All of a sudden, they hear a loud noice. It is the drill sergeant yelling at them. All their heads turn in his direction! He has their attention. It is the same way with a magnet.

When the magnetic field of a magnet acts on the atoms (iron, nickel or cobalt) of a piece of ferromagnetic alloy that has not yet been magentized, even though the atoms can't move from their spots, they rotate to face in the direction of the magnetic field. They temporarily act together, just as the domains inside the permanent magnet do. The fancy scientific name for this is 'magnetic induction'.

Now, the temporary (induced) pole in the piece of metal is attracted to the permanent pole of the permanent magnet. They move together, because the tendency is for the magnetic field to travel as short a distance as possible, and a pole alwasy induces the opposite pole. The two together, so the magnetic field can travel across the shortest possible distance.

When the two are pulled apart, the permanent magnet stops inducing the other piece of metal. The atoms still do not move from their positions, but they go back to pointing in random directions. If the crowd of guys hears a loud noise, they all look that way for an instant, but if they see it was not their drill sergeant, their heads turn back and the go back to whatever they were doing.

By leaving a piece of metal in contact with a magnet for a long time, some of the atoms will line up permanently, and this is one way you can give a weak permanent magnetic field to an ordinary piece of ferromagnetic metal. It is like someone gradually learning discipline and military duty from family tradition, or by reading. It could wear off.

But when a piece of metal is heated almost until it melts and then subjected to a very strong magnetic field it can be made into a permanent magnet. That is like boot camp and being disciplined by a drill sergeant. Then, the change is forever.

If you have a large piece of non-magnetic soft iron, like a big bolt that has been heated in a fire, you can make a magnet out of it. Find where magnetic north is. Stand holding the iron bolt lined up with the north-south magentic poles, and hit the end with a hammer, in the north-south direction. Hit it very hard, several times.

What you just did was to shock the atoms of the bolt, while they were lined up with the Earth's magnetic field. Some of them settled back into new positions inside the bar, because, after all, you did not hit it hard enough to cause it to melt. But some of them lined up with the Earth's magnetic field and will stay that way! It now acts as a weak magnet. If you suspend the bolt from its center by a string, you will see that it acts like a compass needle, linging up with the Earth's magnetic field, so that the Earth's magnetic field can take the 'short cut' through the iron bolt as it travels from one pole to the other. (Remember how I said, the magnetic field wants to travel the shortest distance possible?)

I hope that this helps you to understand. If you have more questions, look up the following words: feromagnetic, field, iron, nickel, cobalt, paramagentic, diamagentic, permeability, retentivity, domain, magnetic moment, induction.

15 NOV 06, 1607 hrs, GMT.

Answer 2

Magnetism is a force that acts at a distance and is caused by a magnetic field. This force strongly attracts ferromagnetic materials such as iron, nickel and cobalt. In magnets, the magnetic force strongly attracts an opposite pole of another magnet and repels a like pole. The magnetic field is both similar and different than an electric field.

A magnetic field consists of imaginary lines of flux coming from moving or spinning electrically charged particles. Examples include the spin of a proton and the motion of electrons through a wire in an electric circuit.

What a magnetic field actually consists of is somewhat of a mystery, but we do know it is a special property of space.

The lines of magnetic flux flow from one end of the object to the other. By convention, we call one end of a magnetic object the N or North-seeking pole and the other the S or South-seeking pole, as related to the Earth's North and South magnetic poles. The magnetic flux is defined as moving from N to S.

Although individual particles such as electrons can have magnetic fields, larger objects such as a piece of iron can also have a magnetic field, as a sum of the fields of its particles. If a larger object exhibits a sufficiently great magnetic field, it is called a magnet.

The magnetic field of an object can create a magnetic force on other objects with magnetic fields. That force is what we call magnetism.

When a magnetic field is applied to a moving electric charge, such as a moving proton or the electrical current in a wire, the force on the charge is called a Lorentz force.

When two magnets or magnetic objects are close to each other, there is a force that attracts the poles together.
When two magnetic objects have like poles facing each other, the magnetic force pushes them apart.

Materials respond differently to the force of a magnetic field. A magnet will strongly attract ferromagnetic materials, weakly attract paramagnetic materials, and weakly repel diamagnetic materials. The orientation of the spin of the electrons in an atom, the orientation of the atoms in a molecule or alloy, and the ability of domains of atoms or molecules to line up are the factors that determine how a material responds to a magnetic field. Ferromagnetic materials have the most magnetic uses. Diamagnetic materials are used in magnetic levitation and MRI.

Ferromagnetic materials are strongly attracted by a magnetic force. The elements iron (Fe), nickel (Ni), cobalt (Co) and gadolinium (Gd) are such materials.

The reasons these metals are strongly attracted are because their individual atoms have a slightly higher degree of magnetism due to their configuration of electrons, their atoms readily line up in the same magnetic direction, and the magnetic domains or groups of atoms line up more readily.

The factors that determine the magnetic property of a material are the configuration of the electrons in the material, the ability of the atoms or molecules in the material to align magnetically, and the alignment of domains or sections in the object. Since alignment is so important in the magnetic properties of materials, liquids and gases are typically not magnetic because their molecules aren't held in place as they are in solids. An exception is in rotating fluids.

Electrons can behave as tiny magnets, each with north (N) and south (S) poles. When an atom's electrons are lined up in the same orientation, with most having their N pole facing one direction, the atom becomes like a magnet, with N and S poles. It is also possible for the electrons to be in various directions, making the atom not magnetic.

Think that just about covers it.

Answer 3

magnets atteact metal coz theres a pulling force beetween the magnet - which likes metal

Answer 4

polarity

Answer 5

polariaty it's as simple as that!