Unit 2 · 5 lessons
Structure and Properties of Matter
How the arrangement of electrons inside atoms decides how atoms bond, what shape molecules take, and why a substance is a gas, a brittle crystal, a hard gem or a shiny metal.
- 52 practice questions
- 44 flashcards
Lessons
- 1From Rutherford to the Quantum AtomHow the gold foil experiment revealed the nucleus, how Bohr used the line spectrum of hydrogen to propose fixed energy levels, where the Bohr model breaks down, and how the quantum mechanical model replaced orbits with orbitals.10 questions
- 2Electron ConfigurationsUsing the aufbau principle, the Pauli exclusion principle and Hund's rule to write full and noble-gas configurations and orbital diagrams, handling the chromium and copper exceptions and ions, and linking configurations to the s, p, d and f blocks and periodic trends.10 questions
- 3Molecular Shape and PolarityPredicting the three-dimensional shapes of molecules and ions with VSEPR theory for two to six electron groups, including lone pairs and expanded octets, then combining shape with electronegativity to decide whether a molecule is polar.11 questions
- 4Intermolecular Forces and Types of SolidsLondon dispersion forces, dipole-dipole forces and hydrogen bonding; how they and the bonds inside substances explain melting point, boiling point, hardness, solubility and conductivity; the four types of solids; and materials designed from an understanding of structure.10 questions
- 5Seeing Structure: Spectroscopy and Instrumental AnalysisHow chemists identify substances they cannot see: atomic absorption spectroscopy for trace metals such as lead in water, infrared spectra for functional groups, mass spectrometry for molar mass and isotope patterns, NMR and its medical cousin MRI, and X-ray crystallography from Dorothy Hodgkin to Rosalind Franklin.11 questions