I’m having a hard time wrapping my head around classifying metals. So far, I’ve seen two divisions:
1. Pure metals and Alloys
2. Ferrous and Non-ferrous
But I haven’t exactly seen a source that takes both classification divisions into account. Sources keep saying ferrous metals contain iron, so is iron the only pure metal that’s ferrous? Is iron even a ferrous metal? What about the other magnetic metals like nickel and cobalt?
In: Chemistry
Just to add to the numerous other comments on magnetism.
The rabbit hole goes deeper.
Ferrous, as described, means that the material is or contains iron.
Ferromagnetic means the material is attracted to magnets. It’s named after iron, but include nickel and cobalt.
Here’s where the rabbit hole begins.
When we say something is ‘magnetic’ we commonly mean ‘ferromagnetic’.
But there are two other related phenomena.
Diamagnetic materials are weakly repelled by magnetic fields. Not attracted. Copper is diamagnetic. But you’d hardly ever notice without extremely strong magnetic fields.
And then the weird one. Paramagnetic. These materials don’t get attracted to magnets or repelled by magnets but resist *changes* in magnetic fields. Aluminum is an example.
So here’s an example of an experiment you can do.
Take three tubes or pipes. A copper pipe, a steel pipe, and an aluminum tube. You can find all of these at your local hardware store.
Hold the pipe vertically and drop a rare earth magnet into the top of each tube.
The magnet falls straight through the copper pipe, sticks to the top of the steel pipe, and the cool one you wanna show your kids – floats slowly down the aluminum tube to the bottom. So slow you can drop it with one hand, and easily reach down and catch it with the same hand.
Then put the pipes back on the shelf. You didn’t think you needed to buy them and bring them home, did you?
Latest Answers