Transition Elements
Transition Elements (d-block elements, Groups 3-12)
High Density
Transition elements have high densities due to their higher atomic masses and closely packed structures. Examples include:
- Iron (Fe): 7.87 g/cm³
- Tungsten (W): 19.3 g/cm³
High Melting Points
The strong metallic bonding from partially filled d-sub shells results in high melting points for transition elements. Examples include:
- Tungsten (W): 3422°C
- Platinum (Pt): 1768°C
Variable Oxidation States
Transition elements exhibit variable oxidation states due to the participation of d-sub shells in bonding along with s-sub shells. Examples include:
- Iron (Fe): +2 and +3
- Copper (Cu): +1 and +2
Colored Compounds
Transition elements often form vibrant colored compounds. Examples include:
- Copper compounds: Blue or green
- Chromium compounds: Red or green
Catalytic Properties
Transition elements are widely used as catalysts in various industrial processes. Examples include:
- Iron: Haber Process (ammonia synthesis)
- Platinum and Palladium: Catalytic converters (emission reduction)
- Nickel: Margarine manufacture
- Platinum: Contact process (sulfuric acid production)