Gallium is a metallic element designated by the symbol, "Ga" it's atomic number is 31, and has an atomic weight of 69.72. Gallium metal can easily melt on the palm of the hand , because of its low melting point ( 29.76 °C ). If you hold a solid gallium crystal in your hand, your own body temperature will cause it to slowly melt into a silvery metallic puddle. Put it into a dish or a mold, and it freezes back into a solid. Gallium isn't toxic as well as won't cause you to crazy like mercury does. And if you get bored with it, you can melt it onto glass and make yourself a mirror.