| Term | Definition |
|---|---|
| atomic motion | The movement and collisions of atoms within a gas that produce forces and pressure. |
| average kinetic energy | The mean kinetic energy of all atoms in a system, which characterizes the temperature of that system. |
| collisions | Interactions between gas atoms or between atoms and container surfaces that involve the exchange of momentum and forces. |
| conservation of momentum | A principle stating that the total momentum of an isolated system remains constant in the absence of external forces. |
| ideal gas | A theoretical gas whose atoms follow the kinetic theory model and obey the relationship between temperature, kinetic energy, and molecular speed. |
| Maxwell-Boltzmann distribution | A graphical representation showing the distribution of energies and speeds of atoms at a given temperature. |
| perpendicular components | The components of forces exerted by gas atoms that are directed perpendicular to a surface, which contribute to pressure. |
| pressure | The force per unit area exerted by a gas on a surface, resulting from collisions of gas atoms with that surface. |
| root-mean-square speed | The speed corresponding to the average kinetic energy of atoms in an ideal gas, related to temperature by the equation v_rms = √(3k_B T/m). |
| temperature | A measure of the average kinetic energy of the atoms within a system. |
| Term | Definition |
|---|---|
| absolute zero | The temperature at which an ideal gas would have zero pressure, extrapolated from a graph of pressure versus temperature. |
| elastic collision | A collision between gas atoms in which kinetic energy is conserved, a key assumption in the ideal gas model. |
| ideal gas | A theoretical gas whose atoms follow the kinetic theory model and obey the relationship between temperature, kinetic energy, and molecular speed. |
| instantaneous velocities | The random velocities of individual gas atoms at any given moment, assumed to vary randomly in the ideal gas model. |
| moles | A unit of measurement for the amount of substance, representing the number of particles in a gas sample used in the ideal gas law. |
| pressure | The force per unit area exerted by a gas on a surface, resulting from collisions of gas atoms with that surface. |
| temperature | A measure of the average kinetic energy of the atoms within a system. |
| volume | The space occupied by a gas, one of the key variables in the ideal gas law. |
| Term | Definition |
|---|---|
| conduction | A thermal process by which energy is transferred between systems or within a system through direct contact without bulk motion of material. |
| convection | A thermal process by which energy is transferred through the bulk motion of a fluid (liquid or gas). |
| cooling | The transfer of energy out of a system through thermal processes. |
| heating | The transfer of energy into a system through thermal processes. |
| radiation | A thermal process by which energy is transferred through electromagnetic waves without requiring a medium. |
| temperature difference | The difference in thermal energy between two systems that drives the spontaneous transfer of energy from the higher-temperature system to the lower-temperature system. |
| thermal contact | A condition where two systems are positioned such that thermal processes can transfer energy between them. |
| thermal equilibrium | A state in which an object maintains a constant temperature and emits energy at the same rate it absorbs energy. |
| Term | Definition |
|---|---|
| adiabatic process | A thermodynamic process in which no energy is transferred to or from the system through thermal processes. |
| center of mass | The point that represents the average position of all the mass in a system. |
| closed system | A system that can exchange energy with its surroundings but not matter. |
| conservative forces | Forces for which the work done is independent of the path taken, such as gravitational and electrostatic forces. |
| first law of thermodynamics | A restatement of conservation of energy that accounts for energy transferred into or out of a system by work, heating, or cooling. |
| ideal gas | A theoretical gas whose atoms follow the kinetic theory model and obey the relationship between temperature, kinetic energy, and molecular speed. |
| internal energy | The sum of the kinetic energy and potential energy of all the objects and their configurations that make up a system. |
| isobaric process | A thermodynamic process in which the pressure of a system remains constant. |
| isolated system | A system that does not exchange energy or matter with its surroundings. |
| isotherm | A line of constant temperature on a pressure-volume diagram. |
| isothermal process | A thermodynamic process in which the temperature of a system remains constant. |
| isovolumetric process | A thermodynamic process in which the volume of a system remains constant. |
| kinetic energy | The energy of motion possessed by an object due to its velocity. |
| monatomic gas | An ideal gas composed of single atoms rather than molecules. |
| potential energy | The energy stored in the configuration or arrangement of objects within a system. |
| PV diagram | A pressure-volume graph used to represent and visualize thermodynamic processes. |
| thermodynamic processes | Processes that describe how a system changes in terms of pressure, volume, temperature, and internal energy. |
| work done on a system | Energy transferred to a system through mechanical means, calculated as W = -PΔV for constant or average external pressure. |
| Term | Definition |
|---|---|
| conduction | A thermal process by which energy is transferred between systems or within a system through direct contact without bulk motion of material. |
| intrinsic property | A characteristic of a material that is independent of the amount of material present and depends on the arrangement and interactions of its atoms. |
| rate of energy transfer | The amount of thermal energy transferred per unit time, measured in watts or joules per second. |
| specific heat | An intrinsic property of a material that quantifies the amount of energy required to change the temperature of a unit mass of that material by one degree. |
| temperature change | The difference in temperature of an object, represented as ΔT, which is directly related to the energy required to heat or cool the object. |
| temperature difference | The difference in thermal energy between two systems that drives the spontaneous transfer of energy from the higher-temperature system to the lower-temperature system. |
| thermal conductivity | An intrinsic property of a material that describes how readily heat energy is transferred through it by conduction. |
| Term | Definition |
|---|---|
| closed system | A system that can exchange energy with its surroundings but not matter. |
| entropy | A measure of the tendency of energy to spread out or disperse, and the unavailability of some of a system's energy to do work. |
| isolated system | A system that does not exchange energy or matter with its surroundings. |
| localized energy | Energy concentrated in a specific region or form that tends to disperse and spread out over time. |
| reversible process | A process in which a system can return to its original state without any net change in entropy of the universe. |
| second law of thermodynamics | The principle stating that the total entropy of an isolated system can never decrease and remains constant only when all processes are reversible. |
| state function | A property of a system that depends only on the current state or configuration of the system, not on how the system reached that state. |
| thermodynamic equilibrium | The state in which a system has maximum entropy and no net changes occur in its macroscopic properties. |