The Covalent Model
The language of organic and inorganic chemistry — from dot-and-cross to 3D architecture.
SL & HL Core
2.2.1 Covalent Bond & Lewis Formulas
Electrostatic attraction, octet rule, drawing Lewis structures.
→2.2.2 Multiple Bonds
Bond number vs length vs strength relationship.
→2.2.3 Coordination Bonds
Dative covalent bonds — NH₄⁺ and CO examples.
→2.2.4 VSEPR Model
Predicting molecular geometry from electron domains.
→2.2.5 Bond Polarity
Electronegativity difference and partial charges.
→2.2.6 Molecular Polarity
Dipole moments and symmetry cancellation.
→2.2.7 Giant Covalent Structures
Diamond, graphite, silicon dioxide, graphene.
→2.2.8 Intermolecular Forces
London dispersion, dipole-dipole, hydrogen bonding.
→2.2.9 Physical Properties
Linking IMFs to boiling points, solubility, viscosity.
→2.2.10 Chromatography
Separation by polarity — Rf values and applications.
→HL Extensions
2.2.11 Resonance
Delocalization, resonance structures, average bond order.
→2.2.12 Benzene
Kekulé vs delocalized model, evidence, stability.
→2.2.13 Expanded Octet & Hybridization
d-orbital participation, 5 & 6 electron domains.
→2.2.14 Formal Charge
Selecting the best Lewis structure.
→2.2.15 Sigma & Pi Bonds
Orbital overlap — head-on vs lateral.
→2.2.16 Hybridization
sp, sp², sp³ — predicting from structure.
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