SUMMARY

A consolidated, bullet-point restatement of every idea developed across the unit: heat is energy in transit (never a stored quantity) flowing hot-to-cold; work transfers energy without requiring a temperature difference; temperature fixes the direction of heat flow; the ideal gas law $PV=NkT=\mu RT$ holds only at thermodynamic equilibrium; heat capacity, specific heat capacity and molar specific heat capacity measure how much heat raises temperature by 1 K; thermal expansion changes shape/area/volume with temperature, with water's anomalous exception; latent heat capacity changes phase, not temperature; calorimetry measures heat exchanged; heat transfers by conduction, convection and radiation, with Stefan-Boltzmann ($E=\sigma T^4$) and Wien's ($\lambda_{max}T=b$) laws governing radiation; thermodynamic equilibrium requires thermal, mechanical and chemical equilibrium together; the zeroth law underlies temperature measurement; internal energy is kinetic plus potential molecular energy; Joule linked mechanical energy to internal energy; the first law is energy conservation including heat, $\Delta U=Q-W$, with work $=\int P\,dV$ (area under the P-V curve); $s_p>s_v$ always; the four named processes (isothermal/isobaric/isochoric/adiabatic) each fix one variable, with isobaric doing the most work and adiabatic the least; a cyclic process has zero net $\Delta U$, its net work equalling the enclosed P-V loop area; all natural processes are irreversible; heat engines convert heat to work, with …