Every magnet has a north pole and a south pole that cannot be separated.

The longer version

Magnetic poles always come in pairs because magnetism arises from moving electric charge in loops. Every known magnetic source has a field that leaves at one end and returns at the other, so cutting a bar in half simply produces two smaller bars, each with both ends again. No isolated pole has ever been detected.

That pairing is written into the equations describing electromagnetism, which forbid a lone pole in ordinary conditions. Some theories predict such particles, but none have been observed. A practical consequence is that a broken magnet still functions, merely with a weaker reach than before.

Where this entry sits

Everyday physics and chemistry hide small wonders in plain sight, from kitchen reactions to the light in the sky. These short facts explain matter, energy, electricity, magnets, sound, and the simple units we use to measure the world. The full list sits on the Science and Physics page, where every entry is listed in order.