1.a. Give the formula of a noble gas which,
[3] although not radioactive itself, is 
    produced by radioactivity.                        He or Ar


  b. Give the formula of one known inter-
    halogen which contains no fluorine.     ICl, ICl3, IBr or BrCl


  c. What physical property was first used
    to show that the noble gases were new
    elements?                                  Atomic spectra


2.  Complete and balance TWO of the following equations:
[4]

 a.  XeF2(s) +  SF4(g) --->  SF6(g) +  Xe(g)          


 b.  IF5(l) + 3H2O(l) --->  HIO3(aq) + 5HF(aq)


 c. 4XeO3(aq) + 12OH-(aq) ---> 3XeO64-(aq) + Xe(g) + 6H2O(l)  


3.  Describe or sketch the molecular structures of TWO of the
[3] following showing the positions of lone pairs if any are
    present:

 a. XeOF4     AXY4E     Square pyramid with =O at apex and 4F    
                        atoms in base. Lone pair below base      
                        opposite O. (Pseudo-octahedral with lone 
                        pair opposite oxygen.)


 b. ICl4-     AX4E2     Square planar with lone pairs above
                        and below plane.  (Pseudo-octahedral
                        with lone pairs opposite each other.)


 c. BrF2+     AX2E2     Atoms bent F-Br-F
                         (Pseudo-tetrahedral.)