2.1  The mass of an atom is concentrated in its minute, positively charged nucleus
2.2  The electron configuration of an atom can be deduced from its atomic number.
12.1  The quantized nature of energy transitions is related to the energy states of electrons in atoms and molecules.

3.1  The arrangement of elements in the Periodic Table helps to predicttheir electron configuration.
3.2  Elements show trends in their physical and chemical properties across periods and down groups.
13.1  The transition elements have characteristic properties; these properties are related to their all having incomplete d sub-levels.
13.2  d orbitals have the same energy in an isolated atom, but split into two sub-levels in a complex ion. The electric fi eld of ligands cause the d orbitals in complex ions to split so that the energy of an electron transition between them corresponds to a photon of visible light.

 4.1  Ionic compounds consist of ions held together in lattice structures by ionic bonds.
4.2  Covalent compounds form by the sharing of electrons.
4.3  Lewis (electron dot) structures show the electron domains in the valence shell and are used to predict molecular shape.
4.4  The physical properties of molecular substances result from different types of forces between their molecules.
4.5  Metallic bonds involve a lattice of cations with delocalized electrons.
15.1  Larger structures and more in-depth explanations of bonding systems often require more sophisticated concepts and theories of bonding.
15.2  Hybridization results from the mixing of atomic orbitals to form the same number of new equivalent hybrid orbitals that can have the same mean energy as the contributing atomic orbitals.