Why do some metals form magnetic bonds?

Some metals form magnetic bonds due to the alignment of unpaired electrons in their atomic structure.

In more detail, magnetism in metals is a result of the behaviour of electrons, which are subatomic particles that orbit the nucleus of an atom. Electrons have a property called spin, which can be thought of as a tiny magnetic field. In most atoms, electrons are paired up and their spins cancel each other out, making the atom non-magnetic. However, in some metals like iron, nickel, and cobalt, there are unpaired electrons whose spins align in the same direction. This alignment creates a net magnetic field, causing the metal to exhibit magnetic properties.

The alignment of these unpaired electrons is influenced by the metal's crystal structure. In ferromagnetic metals (those that form permanent magnets), the atomic structure allows these unpaired electrons to align over large regions known as magnetic domains. When these domains are aligned by an external magnetic field, the metal becomes magnetised.

In contrast, other metals like copper and gold have paired electrons, so their spins cancel each other out and they do not form magnetic bonds. There are also metals that are paramagnetic, where the unpaired electrons align only in the presence of an external magnetic field, and diamagnetic metals, where all electrons are paired and they slightly repel magnetic fields.

In summary, whether a metal forms magnetic bonds or not depends on the arrangement and behaviour of its electrons, particularly whether they are paired or unpaired, and how they align in relation to each other. This is influenced by the metal's atomic and crystal structure.