Molecular structure

Definition

The molecular structure describes the three-dimensional arrangement of atoms within a molecule. It determines the molecule's shape, bond angles, and overall geometry.

5 Must Know Facts For Your Next Test

1. Molecular structure is influenced by the types of chemical bonds (covalent, ionic, etc.) and the spatial arrangement of these bonds.
2. VSEPR (Valence Shell Electron Pair Repulsion) theory is used to predict the geometry of molecules based on electron-pair repulsion.
3. Formal charges help determine the most stable resonance structure for a molecule by evaluating charge distribution.
4. Polarity of a molecule depends on both its molecular geometry and the electronegativity differences between bonded atoms.
5. The presence of lone pairs can significantly alter bond angles, resulting in deviations from idealized geometries.

Review Questions

• How does VSEPR theory explain the shape of molecules?
• What role do formal charges play in determining molecular structure?
• How can you determine if a molecule is polar or non-polar based on its structure?

Related terms

VSEPR Theory: A model used to predict the geometry of individual molecules based on electron-pair repulsion around a central atom.

Formal Charge: A theoretical charge assigned to an atom in a molecule, calculated as: Formal Charge = (Valence electrons) - (Non-bonding electrons + Bonding electrons/2).

Resonance Structure: Different Lewis structures for a single molecule that show delocalization of electrons within the molecule.