The First Law of Thermodynamics Part 1: Collecting All Laws/Formulas in the World (1/100)

The First Law of Thermodynamics is the thermodynamic expression of the law of conservation of energy, which states that energy can neither be created nor destroyed, only converted from one form to another, and its total amount is always conserved. It signifies the relationship where supplied thermal energy and work are converted into changes in internal energy. Basic Formula Q = ΔU + W (Heat absorbed by the system = Change in internal energy + Work done by the system) Heat (Q): Thermal energy supplied/released from the outside Internal Energy (ΔU): Energy that changes according to the kinetic state of gas molecules (proportional to absolute temperature) (Temperature rises -> Gas molecules move actively -> Internal energy increases Temperature drops -> Gas molecules move less -> Internal energy decreases) Calculation Formula: ΔU = ± (+ indicates energy inflow/increase, - indicates energy outflow/decrease) 3/2 × n (moles of gas) × R (gas constant) × T (absolute temperature of gas) = 3/2 × N (number of molecules) × K (Boltzmann constant) × T (absolute temperature of gas) = 3/2 × P (pressure) × V (volume) Work (W): Work done by or on the surroundings as the gas expands or contracts (Key gas state change processes)