[Nosh]

Chemistry magnetism question .. please help ?
a short explanation of paramagnetism, diamagnetism, and ferromagnetism... I dont really understand them.

how do they relate to the atomic theory ? I dont really see a connection.

[Vidya]

For this you need to know Molecular orbital theory.How to arrange electrons in M.O?
If unpaired electrons are there in M.O -paramagnetic
If no unpaired electrons are there in M.O-diamagnetic

[Arkcon]

This is a pretty common question on this board, you might want to try the search function, for the individual topics, and see what you'll find.  Often, whenever someone asks for 5 individual definitions, we like to send them to their textbook/class notes, or to wikipedia, or direct them to Goggle for another information website.  That may not seem very helpful, but it would be a lot of typing to explain it for you.  Can you ask more limited questions, as in, you already know ..., but you're unclear on ...;  some sort of questions along that line.