What you’ll learn17 learning objectivesChoose one objective for a focused lesson, or study the complete topic.—B.1.1—Molecular states• Describe solids, liquids and gases using molecular theory.Syllabus objective—B.1.2—Density• Density: ρ=m/V.Syllabus objective—B.1.3—Temperature scales• Use Kelvin and Celsius temperature scales.Syllabus objective—B.1.4—Temperature scale changes• Temperature change has the same size in Kelvin and Celsius.Syllabus objective—B.1.5—Kelvin temperature and kinetic energy• Kelvin temperature measures average particle kinetic energy: Ek=3/2 kBT.Syllabus objective—B.1.6—Internal energy• Internal energy = intermolecular potential energy + random molecular kinetic energy.Syllabus objective—B.1.7—Thermal transfer direction• Temperature difference sets the net direction of thermal energy transfer.Syllabus objective—B.1.8—Phase change• Phase change changes particle behaviour via energy transfer at constant temperature.Syllabus objective—B.1.9—Specific heat and latent heat• Use Q=mcΔT for temperature change and Q=mL for phase change.Syllabus objective—B.1.10—Thermal transfer mechanisms• Conduction, convection and thermal radiation are the primary mechanisms for thermal energy transfer.Syllabus objective—B.1.11—Conduction• Conduction: the difference in the kinetic energy of particles.Syllabus objective—B.1.12—Conduction rate• Conduction rate depends on material, area and temperature gradient: ΔQ/Δt = kAΔT/Δx.Syllabus objective—B.1.13—Convection• Qualitative description of thermal energy transferred by convection due to fluid density differences.Syllabus objective—B.1.14—Black-body radiation• Black-body radiation power follows Stefan-Boltzmann law: L=σAT^4.• Applies to emission of electromagnetic waves from a black-body surface.Syllabus objective—B.1.15—Apparent brightness• Concept of apparent brightness b.Syllabus objective—B.1.16—Luminosity and brightness• Apparent brightness relation: b = L/(4πd^2).Syllabus objective—B.1.17—Wien’s displacement law• Use black-body spectrum and Wien’s law: λmaxT = 2.9x10^-3 m K.• Use λmax to infer black-body temperature.Syllabus objective