METALS
'(<a href="http://www.j-archive.com/media/2010-09-17_DJ_04.jpg" target="_blank">Kelly of the Clue Crew demonstrates a science experiment. </a>)  When you hold <a href="http://www.j-archive.com/media/2010-09-17_DJ_04a.jpg" target="_blank">ferrofluid</a> over a magnet,<br /> it spikes and marks the lines of the magnetic field because ferrofluid contains nanoparticles of <a href="http://www.j-archive.com/media/2010-09-17_DJ_04b.jpg" target="_blank">this</a> metallic element,  symbol Fe'
iron