Science, Tech, Math › Science The Science of How Magnets Work Share Flipboard Email Print Andrew Brookes/Getty Images Science Chemistry Basics Chemical Laws Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated September 05, 2019 The force produced by a magnet is invisible and mystifying. Have you ever wondered how magnets work? Key Takeaways: How Magnets Work Magnetism is a physical phenomenon by which a substance is attracted or repelled by a magnetic field.The two sources of magnetism are electric current and spin magnetic moments of elementary particles (primarily electrons).A strong magnetic field is produced when the electron magnetic moments of a material are aligned. When they are disordered, the material is neither strongly attracted nor repelled by a magnetic field. What Is a Magnet? A magnet is any material capable of producing a magnetic field. Since any moving electric charge generates a magnetic field, electrons are tiny magnets. This electric current is one source of magnetism. However, the electrons in most materials are randomly oriented, so there is little or no net magnetic field. To put it simply, the electrons in a magnet tend to be oriented the same way. This happens naturally in many ions, atoms, and materials when they are cooled, but isn't as common at room temperature. Some elements (e.g., iron, cobalt, and nickel) are ferromagnetic (can be induced to become magnetized in a magnetic field) at room temperature. For these elements, the electrical potential is lowest when the magnetic moments of the valence electrons are aligned. Many other elements are diamagnetic. The unpaired atoms in diamagnetic materials generate a field that weakly repels a magnet. Some materials don't react with magnets at all. The Magnetic Dipole and Magnetism The atomic magnetic dipole is the source of magnetism. On the atomic level, magnetic dipoles mainly are the result of two types of movement of the electrons. There is the orbital motion of the electron around the nucleus, which produces an orbital dipole magnetic moment. The other component of the electron magnetic moment is due to the spin dipole magnetic moment. However, the movement of electrons around the nucleus isn't really an orbit, nor is the spin dipole magnetic moment associated with actual 'spinning' of the electrons. Unpaired electrons tend to contribute to a material's ability to become magnetic since the electron magnetic moment can't be totally canceled out when there are 'odd' electrons. The Atomic Nucleus and Magnetism The protons and neutrons in the nucleus also have orbital and spin angular momentum, and magnetic moments. The nuclear magnetic moment is much weaker than the electronic magnetic moment because although the angular momentum of the different particles may be comparable, the magnetic moment is inversely proportional to mass (mass of an electron is much less than that of a proton or neutron). The weaker nuclear magnetic moment is responsible for nuclear magnetic resonance (NMR), which is used for magnetic resonance imaging (MRI). Sources Cheng, David K. (1992). Field and Wave Electromagnetics. Addison-Wesley Publishing Company, Inc. ISBN 978-0-201-12819-2.Du Trémolet de Lacheisserie, Étienne; Damien Gignoux; Michel Schlenker (2005). Magnetism: Fundamentals. Springer. ISBN 978-0-387-22967-6.Kronmüller, Helmut. (2007). Handbook of Magnetism and Advanced Magnetic Materials. John Wiley & Sons. ISBN 978-0-470-02217-7.