I.  Properties of Ionic Compounds
                  A. high melting & boiling points   
                       (above 300°C)
                  B.  most are crystalline solids at room 
                       temperature
                  C.  tend to be soluble (dissolve) in 
                       water
                  D.  can conduct electricity in a molten     
                       state or in solution
                  E.  crystallize as sharply defined particles
                  F.  generally form between metals  
                       (cations) & non-metals (anions)
     II.  Ionic Bonds
      Why do atoms bond?
      To be more stable (like noble gases).
     A. due to transfer of valence electrons
     B. oppositely charged ions (cation, 
          anion) are attracted to each other 
     C. monatomic ions = single atoms with 
          a + or – charge.  Ex:  Ca2+
     D. polyatomic ions = 2 or more bonded  
          atoms carrying a net + or - charge   
          (see ion chart)  Ex:  NH41+
         
        *oxyanions- polyatomic anions     
                 containing oxygen
          Ex:  SO42-
        *the subscripts of a polyatomic ion 
          can never be altered!!
            III.  Writing Chemical Formulas
             A.  Formula unit – simplest whole # 
             ratio of ions that yields a net zero  charge
                 1.  write cation first, then anion
                               1+   2-
                             Li   S
                 2.  determine the number of each ion 
                      that is needed to cancel the charges
                       2 Li1+   1 S2-  =  Li2S
                 3.  use parenthesis () around polyatomic 
                      ions if more than one is needed to 
                      balance the charge.
                         3+      1-
                       Al    NO3   =  Al(NO3)3 
          IV.  Naming Ionic Compounds
          A. Rules
              1. Name the cation first
                  *include Roman numerals for        
              transition metals with more than  
                       1 possible charge.
              2.  Name the anion last
                   * monatomic ions end with –ide
                   * names of polyatomic ions        
                never change!!