Hybrid Atomic Orbitals Lecture Notes

This set of vocabulary flashcards covers the fundamental concepts of hybrid atomic orbitals, including the mathematical basis, specific hybridization types like sp, and experimental evidence from molecules such as water and beryllium chloride.

Wave function ($\psi$)

A mathematical expression containing information about each orbital and the wavelike properties of electrons in an isolated atom.

Hybridization

The process of combining the wave functions for atomic orbitals to produce new mathematical descriptions with different shapes.

LCAO

Linear combination of atomic orbitals; the technique used to mathematically accomplish hybridization.

Hybrid orbitals

The new orbitals that result from the linear combination of atomic orbitals when atoms are bound together in a molecule.

Oxygen valence electron configuration

$1s^2 2s^2 2p^4$, featuring two unpaired electrons in two redundant $2p$ orbitals.

Water ($H_2O$) experimental bond angle

$104.5^\circ$, which contradicts the $90^\circ$ angle predicted by the simple overlap of perpendicular $p$ orbitals.

Tetrahedral bond angle

$109.5^\circ$, the angle predicted when five valence orbitals in an oxygen atom are described as four equivalent hybrid orbitals.

Hybrid orbital formation rule

Hybrid orbitals do not exist in isolated atoms; they are formed only in covalently bonded atoms.

Conservation of orbital number

The number of hybrid orbitals in a set is equal to the number of atomic orbitals that were combined to produce the set.

Hybrid orbital equivalence

All orbitals in a set of hybrid orbitals are equivalent in both shape and energy.

$\sigma$ (sigma) bonds

Bonds formed by the overlap of hybrid orbitals.

$\pi$ (pi) bonds

Bonds formed by the overlap of unhybridized orbitals.

$sp$ Hybridization

The process of mixing one valence $s$ orbital and one valence $p$ orbital to yield two equivalent hybrid orbitals with a linear geometry.

$sp$ hybrid orbital bond angle

$180^\circ$, oriented in opposite directions to accommodate two electron domains.

$BeCl_2$ (gaseous)

A molecule where the central beryllium atom exhibits $sp$ hybridization to form two identical $\sigma$ bonds with chlorine atoms.

Examples of $sp$ hybridized atoms

The mercury atom in $HgCl_2$, the zinc atom in $Zn(CH_3)_2$, and the carbon atoms in $HCCH$ and $CO_2$.