Draw the molecular orbital diagram of Br2
The Correct Answer and Explanation is :
The molecular orbital (MO) diagram for diatomic bromine (Br₂) provides insight into its bonding characteristics by illustrating how atomic orbitals combine to form molecular orbitals. Each bromine atom has 35 electrons, with the valence electrons occupying the 4s and 4p orbitals. When two bromine atoms bond, their atomic orbitals overlap to form molecular orbitals, which can be bonding or antibonding.
Construction of the MO Diagram for Br₂:
- Atomic Orbitals: Each bromine atom contributes seven valence electrons, primarily from the 4p orbitals. These orbitals combine to form molecular orbitals.
- Molecular Orbitals Formation: The combination of atomic orbitals results in the formation of sigma (σ) and pi (π) molecular orbitals. The 4p_z orbitals overlap end-to-end to form σ and σ* (antibonding) orbitals, while the 4p_x and 4p_y orbitals overlap side-by-side to form π and π* orbitals.
- Energy Ordering: In Br₂, the energy ordering of molecular orbitals from lowest to highest is: σ(4s), σ(4s), π(4p_x) = π(4p_y), σ(4p_z), π(4p_x) = π(4p_y), and σ(4p_z). This ordering reflects the relative energies of bonding and antibonding interactions.
- Electron Filling: Br₂ has a total of 14 valence electrons (7 from each atom). These electrons fill the molecular orbitals starting from the lowest energy level, adhering to the Pauli exclusion principle and Hund’s rule. The electron configuration is: σ(4s)², σ(4s)², π(4p_x)² = π(4p_y)², σ(4p_z)², π(4p_x)² = π*(4p_y)².
Implications of the MO Diagram:
- Bond Order: The bond order is calculated as (number of bonding electrons – number of antibonding electrons)/2. For Br₂, this results in a bond order of 1, indicating a single bond between the two bromine atoms.
- Magnetic Properties: All electrons in Br₂ are paired, making it diamagnetic.
- Stability: The filled bonding orbitals and empty antibonding orbitals suggest a stable molecule, consistent with the observed properties of Br₂.
Understanding the MO diagram of Br₂ elucidates its bonding nature, stability, and magnetic properties, providing a comprehensive view of its molecular structure.