Thermal Energy and Nuclear Physics Concepts

A comprehensive set of flashcards covering key vocabulary and definitions related to thermal energy, states of matter, and nuclear physics to aid in exam preparation.

Kinetic Molecular Theory

States that matter is composed of particles that attract each other and have kinetic energy.

Temperature

A measure of the average kinetic energy of the particles in a substance.

Thermal Energy

The total amount of kinetic and potential energy possessed by the particles of a substance.

Melting Point

The temperature at which a solid changes into a liquid.

Freezing Point

The temperature at which a liquid changes into a solid.

Boiling Point

The temperature at which a liquid changes into a gas.

Condensation Point

The temperature at which a gas changes into a liquid.

Heat

The transfer of thermal energy from a warmer object to a colder object.

Thermal Conduction

The transfer of thermal energy that occurs when warmer objects are in physical contact with colder objects.

Convection

The transfer of thermal energy through a fluid, occurring when colder, denser fluid falls and pushes up warmer, less dense fluid.

Convection Current

A current that occurs when a fluid is continuously heated; caused by warmer, less dense fluid being pushed upward.

Radiation

The movement of thermal energy as electromagnetic waves.

Thermal Conductors

Materials, typically metals, that allow thermal energy to pass through them relatively easily.

Thermal Insulators

Materials that do not conduct thermal energy very well.

Vacuum

The best thermal insulator; does not conduct thermal energy.

Specific Heat Capacity (c)

The amount of energy required to increase the temperature of 1 kg of a substance by 1 °C; units are J/(kg·°C).

Quantity of Heat (Q)

The amount of thermal energy transferred from one object to another.

Thermal Expansion

The expansion of a substance as it warms up.

Thermal Contraction

The contraction of a substance when it cools down.

Melting

The process by which a solid changes to a liquid.

Latent Heat (Q)

The total thermal energy absorbed or released when a substance changes state.

Latent Heat of Fusion

The amount of thermal energy required to change a solid into a liquid or vice versa.

Latent Heat of Vaporization

The amount of thermal energy required to change a liquid into a gas or vice versa.

Specific Latent Heat (L)

The amount of thermal energy required for 1 kg of a substance to change from one state into another.

Specific Latent Heat of Fusion (Lf)

The thermal energy required to melt or freeze 1 kg of a substance.

Specific Latent Heat of Vaporization (Lv)

The thermal energy required to evaporate or condense 1 kg of a substance.

Ground State

The state in which all electrons are at their lowest possible energy levels.

Excited State

A state in which one or more electrons are at higher energy levels than in the ground state.

Isotopes

Atoms of the same element that have the same number of protons but different numbers of neutrons.

Radioactive Isotopes

Isotopes that are unstable and undergo spontaneous changes in their nuclear structure.

Radioactivity

The process by which the nucleus of an atom spontaneously disintegrates.

Nuclear Fission

The decomposition of large, unstable nuclei into smaller, more stable nuclei.

Nuclear Reaction

The process by which the nucleus of an atom sometimes changes.

Electrostatic Force

The force of attraction or repulsion due to electric charges.

Strong Nuclear Force

The very strong force of attraction between nucleons.

Gamma (g) Decay

A reaction in which an excited nucleus returns to a lower energy state, releasing a gamma ray.

Half-Life

The average length of time it takes a radioactive material to decay to half its original mass.

Law of Conservation of Mass–Energy

States that mass can transform into energy and vice versa, keeping total mass-energy constant.

Mass Defect

The difference between the calculated mass of an atom and its actual atomic mass.

Binding Energy

The energy used to hold a nucleus together.

Mega-electron Volt (MeV)

The energy required to accelerate an electron through a potential difference of 1 million volts.

Nuclear Fuel

The radioactive material used to power a nuclear reactor.

Chain Reaction

A series of reactions that can repeat over several cycles.

Critical Mass

The amount of nuclear fuel required to cause a chain reaction.

Nuclear Fusion

A nuclear reaction in which the nuclei of two atoms fuse to form another element.

Magnetic Confinement Fusion

A method using electromagnetic forces to confine fusion fuel in a high-temperature plasma state.

Controlled Nuclear Fusion

The achievement of nuclear fusion reactions in a way that can be sustained.

Heat Capacity

The ability of a substance to store heat.

Thermal Equilibrium

A condition in which all parts of a substance have the same temperature and thermal energy.

Thermal Insulation

The use of materials to reduce heat transfer.

Nuclear Reactor

A device to initiate and control a sustained nuclear chain reaction for energy generation.

Thermal Gradient

The rate of temperature change with distance in a substance.

Phase Change

The transition of a substance from one state of matter to another.

Latent Heat of Vaporization (Lv)

The energy needed per kilogram to evaporate or condense a substance.

Latent Heat of Fusion (Lf)

The energy needed per kilogram to melt or freeze a substance.

Kinetic Energy

The energy that a body possesses due to its motion.

Potential Energy

The stored energy of an object due to its position.

Thermodynamics

The branch of physics that deals with heat, work, and the energy transformations involved.

Thermal Flux

The rate of thermal energy transfer per unit area.

Nucleons

The collective term for protons and neutrons in an atom's nucleus.

Stable Nucleus

A nucleus that does not undergo radioactive decay.

Unstable Nucleus

A nucleus that is prone to disintegrate or undergo radioactive decay.

Electrons

Negatively charged particles that orbit the nucleus of an atom.

Protons

Positively charged particles found in the nucleus of an atom.

Neutrons

Neutral particles found in the nucleus of an atom.

Atom

The smallest unit of matter that retains the properties of an element.

Molecular Structure

The arrangement of atoms within a molecule.

Heat Exchange

The transfer of thermal energy between bodies at different temperatures.

Radiation Transfer

The process of transferring heat through electromagnetic waves.

Thermal Energy Distribution

The spreading out of thermal energy among particles.

Lattice Structure

The ordered arrangement of atoms in a crystalline solid.

Isothermal Process

A process occurring at a constant temperature.

Adiabatic Process

A process in which no heat is exchanged with surroundings.

Thermal Equilibrium Process

The process that occurs when two bodies at different temperatures come into contact.

Fluid Dynamics

The study of fluids in motion and the forces acting on them.

Energy Transfer Mechanisms

The various methods by which energy is transferred between systems.

Electromagnetic Spectrum

The range of all electromagnetic radiation frequencies.

Thermal Radiation

Electromagnetic radiation emitted due to the thermal energy of an object.

Non-Renewable Energy Sources

Energy sources that cannot be replenished in a short time frame.

Renewable Energy Sources

Energy sources that can be replenished naturally in a short time frame.

Thermal Regulation

The ability of a body to maintain its temperature within certain boundaries.

Nucleosynthesis

The process by which new atomic nuclei are created.

Radiative Cooling

The process of heat loss through radiation.

Temperature Gradient

The rate of temperature change in a certain direction.

Thermal Cycling

Repeated heating and cooling of a material.

Matter

Anything that has mass and occupies space.

Thermal Dynamics

The study of heat and energy flow in a system.