Hibob,
Sorry for the delay, but as you probably know ScienceBuddies was down for the weekend.
My name is Manjinder Kandola and I'm a high school student taking advanced physics courses. I'm not exactly an expert, but seeing as how you need an interview asap, I'll try my best to help you. Please make sure to also review edneu's post.
1. Regarding magnetism, I think the fact that electrons can align themselves to certain magnetic fields and thus impart a force on the object is very cool. Normally, gravity is the first force that comes to mind, but gravity is in fact the weakest of the four fundamental forces.
2. I played with magnets as a kid but I didn't really learn about their properties and the science behind them until high school in a physics class.
3-4, 7. (I think the three are related) Magnets are extremely important because of how widely they can be used in everyday life. TV's, computers, and other LED sources rely on magnetic fields to guide electrons to viewing screens. That's why your teachers tell you never to bring a strong magnet close to your computer, it may damage the magnetic field. Furthermore, common generators use magnets to convert energy from natural sources to electricity.
5. The strength of magnetism (given in tesla) varies greatly depending on the nature of the object. Magnetic substances can be labelled ferromagnetic, paramagnetic, and diamagnetic (see
http://en.wikipedia.org/wiki/Magnet#Com ... of_magnets), which are written in decreasing order of strength. Factors that determine strength include the number of valence electrons, the method by which it was magnetized, how close the object is to the magnet, how the atomic structure of the magnet is likely to rearrange itself etc.
6. Magnets are magnetic because they have a magnetic field which ranges from its two poles. Essentially, the inside of a magnet is broken up into domains in which all the electrons have identical spins.
8. Yes, a magnet can become demagnetized. Here's what the Wiki link has to say:
"Magnetized materials can be demagnetized in the following ways:
Heating a magnet past its Curie temperature; the molecular motion destroys the alignment of the magnetic domains. This always removes all magnetization.
Hammering or jarring: the mechanical disturbance tends to randomize the magnetic domains. Will leave some residual magnetization.
Placing the magnet in an alternating magnetic field with an intensity above the materials coercivity and then either slowly drawing the magnet out or slowly decreasing the magnetic field to zero. This is the principle used in commercial demagnetizers to demagnetize tools and erase credit cards and hard disks, and degaussing coils used to demagnetize CRTs."
Hope that helps,
Manjinder