7.3 General Properties of the Transition Elements (d-block) - Physical Properties, Variation in Atomic and Ionic Sizes of Transition Series, Ionisation Enthalpies, Oxidation States, Trends in the M² + /M and M³ + /M² + Standard Electrode Potentials, Trends in Stability of Higher Oxidation States, Chemical Reactivity and EJ Values, Magnetic Properties, Formation of Coloured Ions, Formation of Complex Compounds, Catalytic Properties, Formation of Interstitial Compounds, Alloy Formation