Temperature, Heat Transfer, and Wave Physics

Vocabulary practice flashcards covering states of matter, temperature scales, absolute zero, thermal transfer methods (conduction, convection, radiation), evaporation, wave properties, and the electromagnetic spectrum.

Particle Model

A scientific model that explains state changes in a substance in terms of the arrangement, movement, and energy stored in its particles.

Solid

A state of matter characterized by a fixed shape and volume, little to no particle movement, very little energy, and high difficulty to compress.

Liquid

A state of matter that has a fixed volume but no fixed shape, flows easily, takes the shape of its container, and can be boiled.

Gas

A state of matter with no fixed shape or volume, particles that possess a lot of energy and space to move around, and is easy to compress.

Temperature

A measure of how hot or cold an object is, specifically measuring the average kinetic (motion) energy of the particles inside a substance, typically measured in degrees Celsius ($^\circ\text{C}$).

Heat

The flow or transfer of thermal energy between objects, which always flows from warmer objects to cooler objects.

Thermal Expansion

The principle behind liquid-in-glass thermometers where liquid molecules move faster and occupy more space when heated, causing the liquid to expand up a narrow capillary tube.

Capillary Tube

A very thin glass tube connected to a bulb holding colored alcohol or mercury in a thermometer, along which expanding liquid climbs next to a calibrated scale.

Kelvin Conversion Formula

The mathematical formula used to convert temperature from degrees Celsius to Kelvin: $T(\text{K}) = T(^\circ\text{C}) + 273.15$.

Absolute Zero

The lowest theoretical temperature known ($0\,\text{K}$ or $-273.15^\circ\text{C}$), where particles reach their lowest possible energy state but retain residual zero-point motion due to the uncertainty principle.

Zero-Point Motion

The residual movement of particles that remains at absolute zero because the uncertainty principle forbids a particle from having both a definite position and zero momentum.

Conduction

The process by which thermal energy is directly transmitted through a substance when vibrating particles gain kinetic energy and collide with nearby particles, transferring heat from a hot region to a cold region.

Thermal Conductor

A material that easily transmits heat via particle vibrations; examples include copper, aluminium, gold, iron, silver, and steel.

Convection

Heat transfer in liquids and gases where warmer, less dense fluid particles with high thermal energy rise and take the place of cooler, denser particles with less thermal energy.

Convection Current

The continuous cyclical movement of thermal energy within a liquid or gas caused by the rising of heated, less dense fluid and the sinking of cooler, denser fluid.

Thermal Radiation

The transfer of heat from one place to another by infrared waves that requires no particles and can travel through the pure vacuum of space.

Matte Black Surface

The surface texture and color that acts as the best absorber and best emitter of heat radiation.

Shiny White Surface

A surface finish that acts as a poor emitter and absorber of thermal radiation, instead reflecting heat radiation.

Thermal Imaging Camera

A device that detects thermal energy by capturing invisible infrared radiation emitted by objects above absolute zero and converting it into visible images or temperature readings.

Evaporative Cooling

A cooling mechanism where the hottest, highest-energy liquid particles absorb body heat and evaporate into gas, leaving behind cooler fluid to chill the surface.

Cooling Rate Formula

The rate at which temperature decreases over time, calculated as: $\text{Cool rate} = \frac{\text{Heat loss}}{\text{Time (min)}}$, expressed in units of $^\circ\text{C/min}$.

Wave

An energy transporter that transfers energy from one location to another through regular rhythmic oscillations without permanently transferring matter.

Oscillations

Repetitive movements back and forth in regular rhythms that allow waves to carry energy through space or a medium.

Longitudinal Waves

Waves in which particle vibrations of the medium oscillate parallel to the direction of wave travel (for example, sound waves).

Transverse Waves

Waves where the vibrations or oscillations of the medium or field occur perpendicular (at right angles) to the direction of wave propagation.

Mechanical Waves

Disturbances that require a physical medium (solid, liquid, or gas) to propagate via particle oscillation, such as sound waves, water ripples, and seismic waves.

Electromagnetic Waves

Self-propagating, purely transverse waves formed by coupled electric and magnetic fields oscillating at right angles to each other, capable of traveling through a vacuum at the speed of $300{,}000{,}000\,\text{m/s}$.

Wavelength ($\lambda$)

The exact physical distance occupied by one complete wave cycle.

Amplitude

The maximum displacement of a wave from its equilibrium or rest position.

Frequency

The number of complete wave cycles that pass a fixed reference point every second, measured in Hertz ($\text{Hz}$).

Wave Velocity

The speed at which wave energy propagates through space or a medium, measured in meters per second ($\text{m/s}$).

Crest

The highest point or peak of a transverse wave.

Trough

The lowest point of a transverse wave.

Electromagnetic Spectrum Continuum

The continuous distribution of electromagnetic waves arranged by increasing frequency and energy (and decreasing wavelength): Radio Waves, Microwaves, Infrared, Visible Light, Ultraviolet, X-Rays, and Gamma Rays.

Visible Light Spectrum

The narrow range of electromagnetic waves positioned in the middle of the spectrum (ROYGBIV), where red light has the longest wavelength and violet light has the shortest wavelength.