1. Introduction.- 2. The Electronic Structure of Transition-Metal Atoms.- 2.1 The Principles of the Crystal-Field and Ligand-Field Theories.- 2.2 Experimental Techniques for Investigating the Surface Compounds and Transition-Metal Atoms in Solids.- 3. The Surfaces of Transition-Metal Oxides.- 3.1 Surface Atoms of Transition Metals in Dilute Oxide Systems.- 3.2 Transition-Metal Atoms in Zeolites.- 3.3 The Surface of Simple Transition-Metal Oxide.- 3.4 The Surfaces of Some Complex Oxide Systems.- 3.5 Energy Levels of Transition-Element Ions in the Bulk and on the Surface of Their Oxides.- 4. Adsorption and Catalysis on Oxides of Transition Metals.- 4.1 Application of the Crystal-Field and Ligand-Field Theories to Adsorptive and Catalytic Phenomena.- 4.2 Symmetry and Reactivity of Coordinated and Adsorbed Molecules.- 4.3 Energy Levels of Adsorbed Molecules in the Band Structure of Oxides and Complexes of Transition Elements.- 4.4 Adsorption of Oxygen on Oxides.- 4.5 Adsorption of Olefins on Oxides.- 4.6 Adsorption of Carbon Monoxide by Oxides.- 4.7 Adsorption and Catalysis on the Diluted and the Supported Oxide Systems.- 4.8 Catalysis by Zeolites Containing Ions of Transition Elements.- 4.9 Adsorption and Catalysis on Magnetic and Ferroelectric Oxides.- 5. The Surface of the Transition Metals.- 5.1 The Band Structure of the Transition Metals.- 5.2 The Surface Orbitals of the Transition Metals.- 5.3 The Real Surface of Pure Metals.- 5.4 The Surface of Alloys.- 5.5 Supported Metals.- 5.6 Small Metallic Clusters.- 6. Adsorption and Catalysis on the Transition Metals.- 6.1 The Adsorptive Complexes on the Surface of Transition Metals.- 6.2 The Energy Levels of Adsorbed Particles on Metallic Surfaces.- 6.3 Adsorption of Hydrogen on Pure Metals.- 6.4 Adsorption of Oxygen on PureMetals.- 6.5 Adsorption of Carbon Monoxide on Metals.- 6.6 Adsorption and Catalysis on Alloys.- 6.7 Adsorption and Catalysis on Supported Metals.- 7. Conclusion.- References.