Early metals http://www.copper.org/education/history/g_fact.html
Niels Bohr http://nobelprize.org/nobel_prizes/physics/laureates/1922/bohr-bio.html
Periodic Table http://www.rsc.org/chemsoc/visualelements//pages/pertable_j.htm
Amazing crystals http://www.slideshare.net/random13579/naica-crystal-cave/
Mohs Scale http://mineral.galleries.com/minerals/hardness.htm
Glowing minerals http://mineral.galleries.com/minerals/property/fluoresc.htm
Precipitation http://www.launc.tased.edu.au/online/sciences/PhysSci/pschem/soln/Solutio1.htm
Phosphorus http://www.rsc.org/chemsoc/visualelements//pages/phosphorus.html
Ice crystals http://www.its.caltech.edu/~atomic/snowcrystals/photo2/photo2.htm