Heat and Temperature - Flashcards

A set of vocabulary flashcards covering key concepts from the notes on heat, temperature scales, energy transfer, and the behavior of matter with heat.

James Prescott Joule

English physicist who showed that mechanical energy can be transformed into heat and concluded that heat is a form of energy.

Heat

Thermal energy; the total energy of all the particles in a material or object.

Thermal Energy

Total energy of all the particles in a material or object.

Calorie (cal)

A unit of heat energy; 1 cal = 4.184 joules.

Kilocalorie (kcal)

1000 calories; commonly used to express food energy.

Joule (J)

SI unit of energy; 1 J = 1 N·m.

Thermometer

Device for measuring temperature; early thermometers were invented by Galileo.

Temperature

A measure of how hot or cold something is, typically measured with a thermometer.

Celsius (°C)

Centigrade temperature scale; 0°C is the freezing point and 100°C is the boiling point of water at 1 atm; devised by Anders Celsius.

Fahrenheit (°F)

Temperature scale in which water freezes at 32°F and boils at 212°F at 1 atm; devised by Daniel Gabriel Fahrenheit.

Kelvin (K)

Absolute temperature scale; 0 K is absolute zero; related to Celsius by K = °C + 273.15.

Absolute Zero

The lowest possible temperature where molecular energy is minimal; 0 K.

Celsius to Fahrenheit conversion

F = (C × 9/5) + 32.

Fahrenheit to Celsius conversion

C = (F − 32) × 5/9.

Celsius to Kelvin conversion

K = C + 273.15.

Kelvin to Celsius conversion

C = K − 273.15.

Radiation

Transfer of heat through electromagnetic waves; does not require matter to move.

Conduction

Transfer of heat by direct contact or particle collisions; metals are good conductors; insulators are poor conductors.

Convection

Transfer of heat within a fluid (liquid or gas) by the movement of the fluid itself.

Radiant Energy

Energy transferred by radiation (electromagnetic waves); travels through space and can be absorbed or reflected.

Conductor

Material that conducts heat well (e.g., many metals).

Insulator

Material that poorly conducts heat; examples include vacuum, certain foams, and many plastics.

Expansion

Increase in volume of a substance when heated.

Contraction

Decrease in volume of a substance when cooled.

Phase Change

Change in the molecular structure of a substance when heated or cooled (e.g., melting, freezing, vaporization).

Solid

Definite shape and volume; expands on heating and contracts on cooling.

Liquid

Definite volume but no definite shape; expands on heating and contracts on cooling.

Gas

No definite shape or volume; expands on heating, contracts on cooling, and can be compressed.

Boiling Point

Temperature at which a liquid boils at a given pressure (water boils at 100°C at 1 atm, or 212°F).

Freezing Point

Temperature at which a liquid freezes at a given pressure (water freezes at 0°C at 1 atm, or 32°F).

Specific Heat Capacity

Amount of heat required to raise the temperature of 1 g of a substance by 1°C (units: J/(g·°C)).

Heat Capacity

Amount of heat needed to raise the temperature of a given mass by 1°C; depends on mass and material.

q = m c ΔT

Formula for heat transferred: q is heat, m is mass, c is specific heat capacity, ΔT is change in temperature.