Hey,

 

I recently became interested in Magnets and decided to look upon some videos. I found this one: http://www.metacafe.com/watch/55826/who_can_explain_this and I was wondering how it was done. Someone posted a comment and said that the liquid poured was liquid nitrogen and that the black block was a super conducting material when it was cooled with liquid nitrogen. I'm thinking of showing this example in my science class and would like to know what material that block is made of, or another example of a material that will become a superconductor.

I believe gold is a superconducter.

The explanation of the video is the Meissner effect, see here:

http://en.wikipedia.org/wiki/Meissner_effect

 

There are a few threads on this site about this (and may include the names of common superconducting materials), use the Search button at the top of the page.

 

Here's one site which sells a kit (excl. liquid nitrogen):

http://www.fieldlines.com/other/superconductor.html

(read that page regarding liquid nitrogen)

 

I often see YBCO (Tc of ~92K) written/talked about, not sure about costs or availability though. See here about YBCO:

http://www.physnet.uni-hamburg.de/home/vms/reimer/htc/pt5.html

 

Try doing a google search or look in suitable places where you might buy a superconducting chip from and see what they have on offer.