transition metals

• definition of a transition metal

  d block element that can at least form 1 stable ion with a partially filled d subshell
• what 2 elements are not transition metals and why?

  • scandium: Sc 3+ has an empty d orbital - not partially filled
  • zinc: Zn 2+ has a full d orbital - not partially filled
• 4 characteristic properties of transition metals

  • variable oxidation states
  • forms coloured ions
  • catalytic activity
  • forms complex ions
• why complexes formed from transition metals form coloured ions

  absorb wavelengths of (visible) light

  to promote/excite electrons in d-orbitals

  remaining wavelengths of (visible) light reflected/transmitted
• coloured ions equation

  
• MnO4: Fe - ratio for redox titration

  1:5
• MnO4: C2O4 - ratio for redox titration

  2:5
• MnO4- to Mn2+

  purple ---> colourless