[1] http://www.livescience.com/29377-copper.html

[2] http://en.wikipedia.org/wiki/Copper

[3] http://sciencenotes.org/wp-content/uploads/2013/05/31-Gallium-Tile.pnghttp://www.inorganicventures.com/sites/default/files/Cd.gifhttp://img1.wikia.nocookie.net/__cb20131115041104/marvelcinematicuniverse/images/b/b0/Palladium_Periodic_Table.pnghttp://i1.cpcache.com/product_zoom/709474362/elements_47_silver_square_sticker_3_x_3.jpg?height=250&width=250&padToSquare=truehttp://i1.cpcache.com/product/648632178/periodic_table_zinc_tile_coaster.jpg?height=460&width=460&qv=90http://www.comboutique.com/shop/products/inprint_small/USR58587/20110327230735_28_nickel_t.jpg

[4] http://meetville.com/images/quotes/Quotation-Henry-David-Thoreau-water-leisure-time-Meetville-Quotes-254512.jpg