You can tell how old some coins are by testing them with a magnet. 5p and 10p coins made before January 2012 are not magnetic. 5p and 10p coins made after January 2012 are magnetic. This is ...

Metals are the only substances that are magnetic. But some metals are magnetic and some are not. The most common magnetic metal is iron. You don't see too many objects made of pure iron but you do see ...