Models of the particulate nature of matter
Five sub-topics, from the kinetic model of the three states through to the ideal gas equation. The thread running through all of them: matter is particles, and everything measurable is a consequence of how many there are and how fast they move.
Introduction to the particulate nature of matter · The nuclear atom
S1.3Electron configurations
S1.4Counting particles by mass: the mole
S1.5Ideal gases
Models of bonding and structure
Ionic, covalent and metallic are three models, not three boxes. The last sub-topic makes that explicit: real substances sit on a continuum, and the position on it predicts the properties.
The ionic model
S2.2 Part AThe covalent model — SL core
S2.2 Part BThe covalent model — additional higher level
S2.3The metallic model
S2.4From models to materials
Classification of matter
Two classification systems: the periodic table for elements, functional groups for organic compounds. Both exist because position predicts behaviour — that is the whole claim, and both sub-topics test it.
The periodic table: classification of elements
S3.2 Part AFunctional groups: classification of organic compounds — SL core
S3.2 Part BStereochemistry and spectroscopic identification — AHL
What drives chemical reactions?
Enthalpy alone answers this at standard level and gets it wrong often enough that higher level has to add entropy. The four sub-topics build in that order: energy in and out, energy accounted for around a cycle, energy from fuels, and then the quantity that actually decides.
Measuring enthalpy changes
R1.2Energy cycles in reactions
R1.3Energy from fuels
R1.4Entropy and spontaneity
How much, how fast and how far?
Three separate questions that students routinely merge. Amount is fixed by the equation, rate by the energy barrier, and extent by the equilibrium constant — and none of the three predicts the others.
How much? The amount of chemical change
R2.2How fast? The rate of chemical change
R2.3How far? The extent of chemical change
What are the mechanisms of chemical change?
Four mechanisms classified by what happens to a pair of electrons: transferred as a proton, transferred as an electron, shared one each, or supplied entirely by one partner.