Thermodynamics – Lecture Page 10 Vocabulary

Vocabulary flashcards covering key thermodynamic terms and concepts mentioned on Page 10 of the lecture notes.

Macroscopic Properties

Properties that arise from the collective behaviour of a large number of particles and can be measured directly, e.g., pressure, volume, temperature, composition, colour, refractive index.

Pressure

The force exerted per unit area by particles colliding with the walls of their container; measured in pascals (Pa).

Volume

The three-dimensional space occupied by a system; commonly expressed in litres (L) or cubic metres (m³).

Temperature

A measure of the average kinetic energy of the particles in a system; determines the direction of heat flow.

Composition

The relative proportions of different chemical species present in a system.

Refractive Index

The ratio of the speed of light in vacuum to its speed in a given material; indicates how much light bends when entering the substance.

Zeroth Law of Thermodynamics

If two systems are each in thermal equilibrium with a third system, they are in thermal equilibrium with each other.

Thermal Equilibrium

A state in which no net heat flows between systems because they share the same temperature.

Internal Energy (U)

The total microscopic energy contained in a system (translational, rotational, vibrational, electronic, etc.), excluding macroscopic kinetic and potential energies.

Macroscopic Kinetic & Potential Energy

Energy associated with the bulk motion (velocity) and elevation of an entire system; not included in internal energy calculations.

Ideal Gas Law

The equation of state for an ideal gas: PV = nRT, relating pressure (P), volume (V), amount (n), gas constant (R), and temperature (T).

Internal Energy of a Monatomic Ideal Gas

For a monatomic ideal gas, U = (3⁄2)nRT, representing purely translational kinetic energy.