Theories of Covalent Bonding and Hybridization

Molecular Orbital Theory

Bonding electrons reside in molecular orbitals from atomic orbitals.

Valence Bond Theory

Valence electrons are involved in chemical bonding.

Hybridization

Mixing of atomic orbitals to form hybrid orbitals.

Sigma Bond (σ)

First bond formed by head-on orbital overlap.

Pi Bond (π)

Bond formed by lateral overlap of p or d orbitals.

Orbital Overlap

Atomic orbitals overlap to form covalent bonds.

Bond Pair Electrons

Electrons occupying the overlapped region of orbitals.

Robert S. Mullikan

Developer of Molecular Orbital Theory.

End-to-End Overlap

Overlap type forming sigma bonds.

Sideways Overlap

Overlap type forming pi bonds.

Strength Order of Sigma Bonds

p-p > s-p > s-s in strength.

Hydrogen Atom Configuration

1s1 is the electronic configuration of hydrogen.

Fluorine Atom Configuration

2s2 2px 2py 2pz is fluorine's configuration.

Tetrahedral Hybridization

sp3 hybridization with 109° bond angles.

Trigonal Hybridization

sp2 hybridization with 120° bond angles.

Digonal Hybridization

sp hybridization with 180° bond angles.

Hybrid Orbitals

New orbitals formed from hybridization of atomic orbitals.

Covalent Bond Formation

Result of orbital overlap between two atoms.

Methane (CH4) Structure

Carbon forms four equivalent sp3 hybrid bonds.

Ethylene (C2H4) Structure

Contains sp2 hybrid orbitals with 120° angles.

Acetylene (C2H2) Structure

Contains sp hybrid orbitals with 180° angles.

Electron Spin Pairing

Electrons in overlapping orbitals must have opposite spins.

Orbital Shapes

s = sphere, p = peanut, d = double peanut.

Bonding Electrons

Electrons that participate in bond formation.

Chemical Bonding

Attraction between atoms due to electron sharing.