Science (Heat) - 1st Periodical Examination

Heat

Energy in transit from a medium of high temperature to one of low temperature.

Internal Energy

The energy of an object in the microscopic scale.

External Energy

The energy due to the macroscopic motion of the system as a whole.

Sources of Heat

Sun, Earth's interior, molten volcanic materials, hot springs, geysers, nuclear reactions, friction, and chemical reactions.

Resistance

The ability of conductors to block the passage of an electric current.

Nuclear Reaction

Involves the combination of nuclei of light atoms to form heavier nuclei that release much energy.

Friction

A force that opposes motion and compresses materials

Chemical Reactions

Those of coal, oil, and as with oxygen that produce heat energy and when burned, releases a great amount of heat energy.

Thermal Energy

The part of the internal energy of a system that is equivalent to the total kinetic energy that results from the random movement of atoms and molecules.

Temperature

The quantity that tells how hot or cold an object or a body is compared to a standard.

Thermal Equilibrium

Occurs when two or more bodies in a system have the same temperature and there is no flow of heat.

Conduction

A type of heat transfer from molecule to molecule.

Conductors

Materials through which heat can pass through easily.
(Silver, Gold, Copper, Aluminum, and Mercury)

Silver

The best known heat conductor.

Insulators

Substances that are poor conductors.
(Wood, Glass, Cloth, Plastic and Rubber)

Convection

A method of heat transfer in fluids caused by the continuous circulation of heat.

Radiation

The transfer of heat waves through space.

Calorimeter

An instrument used to measure the quantity of heat given off by a body.

Thermometer

An instrument used to measure temperature.

Temperature Scales

Fahrenheit Scale, Celsius Scale, and Kelvin Scale.

Fahrenheit Scale

Used in the English System.

212°F

Boiling point of water using the Fahrenheit Scale.

32°F

Freezing point of water using the Fahrenheit Scale.

Celsius Scale

Used in the Metric System.

100°C

Boiling point of water using the Celsius Scale.

0°C

Freezing point of water using the Celsius Scale.

Kelvin Scale

One of the seven base SI Units.

373 K

Boiling point of water using the Kelvin Scale.

273 K

Freezing point of water using the Kelvin Scale.

0 K

Kelvin Scale's lowest value.

Absolute Zero

The lowest possible temperature where nothing could be colder and no heat energy remains in the substance.

Specific Heat

The heat capacity of a substance per gram of a substance.

Melting

The process of changing a solid into liquid.

Heat of Fusion

The amount of heat required to melt an object.

Solidification

The process of changing liquids to solids.

Evaporation

The process of converting a liquid into a gas.

Heat of Vaporization

The amount of heat needed for a liquid to evaporate.

Condensation

The process of converting gas to liquid.

Sublimation

The process in which a substance is transformed from the solid phase directly to the gas state without passing the liquid phase.

Deposition

The process in which a substance is transformed from gas to solid without passing the liquid phase.

Expansion

An increase in the size of the body.

Contraction

A decrease in the size of the body.