Foundations

A bound nucleus has less rest mass than its separated nucleons.

A fixed decay probability per time gives a population timescale.

Nuclear rearrangement can release or require energy.

Normalize a scattering rate by incident flux.

Quarks and leptons form three generations.

Gauge fields mediate three interactions; the Higgs is a scalar sector.

A balance rule must name the interaction where it applies.

A periodic crystal potential organizes energies by wavevector and band.

Band occupancy and doping control mobile carriers.

Indistinguishable particles have different equilibrium state populations.

Other electrons modify the attraction experienced by an electron in an atom.

Orbital occupations connect atomic electronic structure with valence chemistry.

Localized orbital overlap and resonance are complementary chemical descriptions.

A molecular orbital description distributes electronic states across a molecule.

Dispersion, dipole interactions and hydrogen bonding influence molecular materials.

Ionic, metallic, molecular and network solids organize common bonding patterns.

Polymers are substances composed of macromolecules with recurring structural units.

Ligand donor atoms surround a central metal in a coordination sphere.

Activity expresses composition relative to a specified thermodynamic standard state.

pH is an activity-based quantity realized through measurement conventions.

An acid–base pair can resist limited changes in solution pH.

An equilibrium product constrains dissolution of a specified solid phase.

Electrode potentials are specified relative to a reference half-cell.

Reversible electrochemical potential depends on activities and temperature.

A mechanism proposes steps that account for an overall chemical transformation.

Many rate constants follow an exponential temperature model over a limited range.

Reaction enthalpies can be combined because enthalpy is a state function.

Phase diagrams describe equilibrium states under stated conditions.

Quantitative analysis needs a validated relation between response and analyte amount.

Differential interactions with mobile and stationary phases separate mixture components.