Electronic Configurations of the d-Block Elements
Introduction to d-Block Elements
The d-block elements, also known as transition elements, are found in groups 3-12 of the periodic
table. They have partially filled d-orbitals in their ground state or in any of their oxidation states.
These elements exhibit unique electronic configurations and properties due to their d-electrons.
General Electronic Configuration
The general electronic configuration of d-block elements is (n-1)d^(1-10) ns^(0-2). The (n-1)d
orbitals are gradually filled as we move across the period.
Exceptions in Electronic Configuration
Some elements exhibit deviations from the expected configuration due to enhanced stability of
half-filled and fully-filled d-orbitals. For example:
- Chromium (Cr): Expected: [Ar] 3d^4 4s^2, Actual: [Ar] 3d^5 4s^1
- Copper (Cu): Expected: [Ar] 3d^9 4s^2, Actual: [Ar] 3d^10 4s^1
Stability of Half-Filled and Fully Filled Orbitals
Half-filled (d^5) and fully filled (d^10) configurations are more stable due to:
- Symmetrical distribution of electrons
- Exchange energy stabilization
- Reduction in electron repulsion
Trends in the d-Block Elements
Some general trends observed in the d-block elements are:
- Gradual increase in effective nuclear charge
- Variable oxidation states due to participation of d and s electrons
- Formation of colored compounds due to d-d transitions
- Magnetic properties based on unpaired electrons
Examples with Configurations
Here are some d-block elements and their electronic configurations:
- Scandium (Sc): [Ar] 3d^1 4s^2
Introduction to d-Block Elements
The d-block elements, also known as transition elements, are found in groups 3-12 of the periodic
table. They have partially filled d-orbitals in their ground state or in any of their oxidation states.
These elements exhibit unique electronic configurations and properties due to their d-electrons.
General Electronic Configuration
The general electronic configuration of d-block elements is (n-1)d^(1-10) ns^(0-2). The (n-1)d
orbitals are gradually filled as we move across the period.
Exceptions in Electronic Configuration
Some elements exhibit deviations from the expected configuration due to enhanced stability of
half-filled and fully-filled d-orbitals. For example:
- Chromium (Cr): Expected: [Ar] 3d^4 4s^2, Actual: [Ar] 3d^5 4s^1
- Copper (Cu): Expected: [Ar] 3d^9 4s^2, Actual: [Ar] 3d^10 4s^1
Stability of Half-Filled and Fully Filled Orbitals
Half-filled (d^5) and fully filled (d^10) configurations are more stable due to:
- Symmetrical distribution of electrons
- Exchange energy stabilization
- Reduction in electron repulsion
Trends in the d-Block Elements
Some general trends observed in the d-block elements are:
- Gradual increase in effective nuclear charge
- Variable oxidation states due to participation of d and s electrons
- Formation of colored compounds due to d-d transitions
- Magnetic properties based on unpaired electrons
Examples with Configurations
Here are some d-block elements and their electronic configurations:
- Scandium (Sc): [Ar] 3d^1 4s^2
