Hybrid Atomic Orbitals Summary

Hybrid Atomic Orbitals

  • Hybridization Concept: Combines atomic orbitals for better bonding descriptions in molecules.

  • Example - Water (H2O):

    • Oxygen: $1s^2 2s^2 2p^4$; two unpaired electrons.

    • Valence bond theory predicts H–O–H angle of 90°, actual measured angle: 104.5°.

  • Quantum Calculations:

    • Wave function ($ psi$) describes electron properties; results in molecular orbitals.

    • Hybridization forms new orbitals from original; called hybrid orbitals.

  • Hybrid Orbitals:

    • Created by combining atomic orbitals (number of hybrids = number of atomic orbitals combined).

    • All hybrid orbitals are equivalent in shape/energy, differing only in orientation.

  • Types of Hybridization:

    • sp Hybridization: Combines one s and one p orbital (linear geometry).

    • sp2 Hybridization: Combines one s and two p orbitals (trigonal planar geometry).

    • sp3 Hybridization: Combines one s and three p orbitals (tetrahedral geometry).

  • Observations:

    • Different types of hybridization are linked to the electron density around central atoms.

    • VSEPR theory used for geometry predictions; bond angles depend on hybridization type.

  • Limitations:

    • Valence bond theory works well for tetrahedral geometries but struggles with octahedral and beyond due to high energy of d-orbitals.