What causes substances like iron to be attracted towards a magnet?
Ferrous magnetism is just that. Ferrous. It has to do with iron. Only ferrous (iron) alloys will be attracted to ferrous magnets. Ferrous magnets are created by “magnetizing” a bar of iron or iron alloy by subjecting it to electric current until its iron atoms line up so that all the magnetic field causes poles in the piece of iron. Iron atoms are special. 🙂 Magnetism exists outside of ferrous magnets, of course. It happens when extra electrons or protons exist within an atom. If the atom is proton-heavy, it is positively charged. If it is electron-heavy, it is negatively charged. Positively charged ions repel other positive ions, and the same is true of negative ions. Cycles can be created between repeling and charging atoms. Hence, electric current. The flow of electric current produces a magnetic field, which is how you can get a magnet (an electromagnet) which attracts non-ferrous items. It is also how the magnetic fields of earth and other celestial bodies work. As the atoms flow