[timchai]

Given that the complex ion [Co(NH3)6]3+ is diamagnetic while the complex ion [CoF6]3-   
               is paramagnetic, write down the 'electrons-in-boxes' representation for the cobalt ion in
               each of these two complex ions.   
i want to ask why they are different , they are Co3+ and how to draw their electron structure ,and tell me how ligand form bond with them (using which orbital ). plz help me

[AWK]

http://en.wikipedia.org/wiki/Crystal_field_theory
http://www.public.asu.edu/~jpbirk/CHM-115_BLB/Chpt24/sld095.htm