Answer
Complexes with strong field ligands are called low-spin complexes and complexes with weak field ligands are called high-spin complexes.
Work Step by Step
In general, complexes with strong field ligands have fewer unpaired electrons compared to the free metal ion and are therefore called low-spin complexes. Complexes with weak field ligands, in contrast, have the same number of unpaired electrons as the free metal ion and are called high-spin complexes. For example,
\[Fe{{\left( {{\left( CN \right)}_{6}} \right)}^{4-}}\]: low-spin complex
\[Fe{{\left( {{H}_{2}}{{O}_{6}} \right)}^{2+}}\]: high-spin complex
