What Is Magnetism? Curious Science Facts Revealed For Kids! | Kidadl


What Is Magnetism? Curious Science Facts Revealed For Kids!

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The phenomenon of magnetism is related to magnets and magnetic fields.

The effect of magnetic fields on matter is fundamental to magnetism. Magnetic fields can be due to a simple bar magnet or the current flowing through a conducting wire.

The term magnet has its roots in the Greek words magnetis lithos, which translates to 'Magnesian stone'. People have been using magnets for various purposes, with historical records of magnet use dating back to 600 BCE. The use of the magnetic compass for navigation purposes was discovered in the 11th century in China and the 12th century in Europe. One of the most familiar examples of magnets is the bar magnets which have magnetic north and south poles and can attract or repel other magnets. However, even though magnets had widespread use, their function could not be explained until the 19th century. In 1819, Danish physicist Hans Christian Ørsted unintentionally discovered magnetic fields around live wires. Later, in 1873, James Clerk Maxwell described the relationship between electricity and magnetism, which was also a part of Einstein's special theory of relativity (1905). Today, magnets find numerous applications in our everyday life. Be it burglar alarms, maglev trains, and MRI, or credit cards, loudspeakers, and microphones, the use of the magnetism knows no bounds!

If you like reading about magnetism, check out other interesting science articles on what is an aurora and what is periodic table.

Definition Of Magnetism With Example

Magnetism is the phenomenon associated with magnetic fields. Electricity and magnetism are the two fundamental aspects of electromagnetic force.

According to the standard definition of magnetism, it refers to the attractive and repulsive forces produced by the motion of electric charge. The region around the moving electric charges consists of both electric and magnetic fields. This magnetic field gives rise to a magnet or magnetic object's ability to repel or attract other magnetic materials. The SI unit of the magnetic field is Tesla (T), named after scientist Nikola Tesla who is best known for his work with alternating current. One Tesla is defined as the magnetic field intensity producing one Newton of force per meter of conductor and per ampere of current.

Magnets are substances that create a magnetic field around them and attract or repel other substances. Many materials that we see around us exhibit the phenomenon of magnetism. Magnetic materials may either attract or repel each other, depending on which portion of the materials are brought close to each other. Moreover, some magnetic materials such as permanent magnets made from iron experience magnetism more strongly than others. A magnet has two end poles (north pole and south pole) and an invisible magnetic field surrounding it. Like magnetic poles repel and unlike magnetic poles attract. Thus, the magnetic north pole of a magnet will be attracted to the magnetic south pole of another magnet and repelled by its north pole. Some of the most well-known magnetic materials include iron, nickel, steel, stainless steel, cobalt, and rare earth metals such as neodymium.

What is magnetism force?

The attractive or repulsive force between charged particles in motion is called magnetic force.

When charged particles move, they either experience an attractive or repulsive force between them. Typically, charged electric particles having the same direction of motion experience an attractive force between them. Alternatively, charged particles moving in opposite directions will have a repulsive force between them. In other words, the magnetic force existing between two charged particles in motion may be described as the effect of the magnetic field created by either charge on the other.

The magnetic force experienced by the second moving particle is dependent on its electric charge, the velocity with which it is moving, the magnetic field generated by the first moving charge, and the sine value of the angle between the direction of the magnetic field and the path of the second particle. Therefore, the force will be greatest when the second particle is traveling at right angles to the magnetic field (Sine 90 degrees = 1) and zero when moving in the same direction as the magnetic field (Sine 0 degrees = 0). The magnetic force is responsible for the attraction of magnets towards certain metals and the action of electric motors.

How does magnetism work?

Like an electric current is produced by the flow of electrons, magnetism results from the spinning of electrons around the nucleus of an atom.

The spin of electrons around the nucleus of an atom generates a small magnetic field. In most materials, electrons spin in random directions, their magnetic forces canceling each other out. However, in the case of magnets, the atoms are arranged in a way that their electrons spin in the same direction. The arrangement and spin of electrons create a force and result in a magnetic field around the magnet. In a simple magnet such as a bar magnet, the magnetic field is depicted by imaginary lines from the north pole to the south pole.

Even though all matter exhibits some degree of magnetism, its magnetic behavior depends on the temperature and the electronic configuration of the atoms. An increase in temperature increases the random thermal motion of the particles and makes it difficult for electrons to align, resulting in reduced magnetic strength. The electronic configuration can either cause the magnetic moments to align, making the matter more magnetic or cancel out magnetic moments, making the material less magnetic.

Depending on the cause of magnetism and magnetic behavior, the main types of magnetism are ferromagnetism, diamagnetism, paramagnetism, ferrimagnetism, and antiferromagnetism. The following is a description of the different types, their properties, and examples.

Ferromagnetism: Ferromagnetic materials have a strong attraction towards magnets and can form permanent magnets. A ferromagnetic material has unpaired electrons and their magnetic moments (spins) tend to align even in the absence of an external magnetic field. Examples of ferromagnetic substances include metals like iron, nickel, cobalt, their alloys, some alloys of manganese, and some rare earth metal alloys.

Diamagnetism: Diamagnetism is the tendency of a material to be repelled by a magnetic field and is mostly observed in materials that do not have unpaired electrons in their atoms. The electron pairs that are present have spin magnetic moments that cancel each other out, resulting in a diamagnetic behavior. In the presence of a magnetic field, a diamagnetic material is weakly magnetized in a direction opposite to that of the applied field. Examples of diamagnetic substances include water, air, gold, copper, and quartz.

Paramagnetism: A paramagnetic material has unpaired electrons that are free to align their magnetic moments. When such a material is placed in a magnetic field, the magnetic moments align and become magnetized in the direction of the applied field. As a result, the material develops a pretty strong attraction for magnets. Examples of paramagnetic substances include molybdenum, magnesium, tantalum, and lithium.

Ferrimagnetism: Like ferromagnets, a ferrimagnetic substance is attracted towards magnets and remains magnetized when removed from a magnetic field. However, neighboring pairs of electrons in ferrimagnetic materials point in opposite directions but do not cancel. The arrangement of atoms in these materials is such that the magnetic moment pointing in one direction is stronger than that pointing in the opposite direction. Ferrimagnetism is observed in ferrites and magnetites.

Antiferromagnetism: The magnetic moments of electrons in antiferromagnetic substances point in opposite directions, resulting in zero magnetic moment and magnetic field. Antiferromagnetic substances include transition metal compounds such as nickel oxide, iron manganese, chromium, and hematite.

Magnetism is phenomenon associated with magnetic fields

Is Earth a magnet?

The Earth's core produces a magnetic field, which is why we can measure magnetic fields on the Earth's surface. So in a way, the Earth can be considered to be a massive and weak magnet.

The liquid outer core of the Earth is composed of molten, conductive iron. Loops of electric currents in this constantly moving molten iron create magnetic fields. Like a magnet, the Earth has north and south magnetic poles. The magnetic south pole is located close to the Earth's geographic north pole. Similarly, the magnetic north is near the Earth's geographic south pole. Like any other magnet, the magnetic lines of force move from the Earth's north magnetic pole to the south. Furthermore, the magnetic field varies in strength on the Earth's surface: it is weakest at the equator and strongest at the poles.

On the surface of the Earth, we can make a compass out of a magnet or magnetized object. The needle of the compass is nothing but a magnetized bit of metal. When perfectly balanced, the needle tends to move and orient itself with the local magnetic field. When the compass needle is not pointing north, magnetic forces will push it to face the north. An important thing to remember is that a compass needle tends to point towards the magnetic north pole and not the geographic north. The difference between the direction of the geographic north pole and where the compass needle points is called declination.

Did you know...

Passing an electric current through a wire produces electromagnetism. Increasing the strength of the current passing through the wire increases the magnetic field's strength.

Magnetic fields are measured using a device called a magnetometer.

Temperature can either weaken or strengthen a magnet's attractive forces. While heating a magnet will weaken its magnetic properties, cooling the magnet or exposing it to low temperatures will result in a strong magnetic field.

A form of magnetite called lodestone is the strongest, naturally-occurring magnet.

Magnets are made from metal elements and their alloys. Different types of magnets have different constituent metals. For example, alnico magnets consist of aluminum, nickel, and cobalt, ceramic magnets consist of iron oxide and ceramic composite, and neodymium magnets contain boron, iron, and the rare earth metal neodymium.

Permanent or hard magnets create magnetic fields at all times, but temporary or soft magnets produce magnetic fields only in the presence of permanent magnetic fields. Temporary magnets lose their magnetic properties when the external field is removed. Iron nails and paper clips are examples of temporary magnets.

If you want to magnetize a metal object, take a bar magnet and stroke it against the metal in one direction. Continue rubbing in the same area and in the same direction until the metal object has achieved magnetization and starts attracting other metal pieces.

Here at Kidadl, we have carefully created lots of interesting family-friendly facts for everyone to enjoy! If you liked our suggestions for What Is Magnetism? Curious Science Facts Revealed For Kids!, then why not take a look at 19 Fun February Birthday Facts That You Won't Believe or Puerto Rico Culture Facts: Curious Details On Puerto Ricans Revealed!?

<p>With a Master of Arts in English, Rajnandini has pursued her passion for the arts and has become an experienced content writer. She has worked with companies such as Writer's Zone and has had her writing skills recognized by publications such as The Telegraph. Rajnandini is also trilingual and enjoys various hobbies such as music, movies, travel, philanthropy, writing her blog, and reading classic British literature.&nbsp;</p>

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