  | 
                Chemical Symbol: He 
                     
                    Description: 
                  Helium is   the lightest element after hydrogen, and represents only 5 ppm of the   atmosphere. It is a nonflammable and nontoxic gas. Helium is inert to   chemical reactions and radiations. Out of all inert gases, helium has   the highest thermal conductivity. The gas is only slightly soluble in   water. 
   
   
  Uses: 
                  Helium is used for welding and as a   lifting gas in balloons. It is also used as a coolant in nuclear   reactors and for growing germanium and silicon crystals for transistors,   as well as the production of some metals such as titanium and   zirconium. Helium is also used for filling cold-water fluorescent lamps   as well as laser and fiber optic production. When mixed with oxygen it   can be used for diving and medical purposes. Liquid helium is used for   cooling superconductive magnets.  |