What are transition elements?

Transition elements have partially filled d orbitals in their ground state or in a common oxidation state. They occupy the d-block (Groups 3–12).

Characteristic Properties:

• Variable oxidation states
• Coloured compounds (d-d electron transitions)
• Good catalysts (Fe in Haber process, Ni in hydrogenation)
• High melting/boiling points
• Form complex ions
• Magnetic properties

Examples: Fe, Cu, Zn, Mn, Cr

Transition elements are d-block elements with partially filled d orbitals, known for variable valencies, coloured compounds, and catalytic activity.