Chapter 3 Vocabs – Flashcards

 the erratic, jerky movement of tiny particles suspended in a fluid caused by the random impacts of individual molecules in thermal motion.

the energy of motion.

a measure of the average kinetic energy of atoms or molecules.

scattered equally among all possible choices with no organized pattern.

a temperature scale with 180 degrees between the freezing and boiling points of water; water freezes at 32°F and boils at 212°F.

a temperature scale with 100 degrees between the freezing and boiling points of water; water freezes at 0°C and boils at 100°C.

an instrument that measures temperature.

an electronic sensor that measures temperature by detecting changes

in electrical resistance.

 an electronic sensor made of two different metals that detects a temperature-dependent voltage across them.

 the lowest possible temperature, at which the energy of molecular motion is essentially zero, or as close to zero as allowed by quantum theory.

a temperature scale that starts at absolute zero and has the same unit intervals as the Celsius scale: TKelvin = TCelsius + 273.

thermal energy, energy resulting from temperature; the total energy in random molecular motion contained in matter.

the fundamental SI unit of energy (and heat).

 an older unit of heat

a large unit of heat.

 law of nature that states that energy (heat) spontaneously flows from higher temperature to lower temperature.

 a group of interacting objects and effects that are selected for investigation.

a system which can exchange matter and energy with the surroundings.

a system which can exchange only energy with the surroundings.

 a system in which neither matter nor energy can be exchanged with the surroundings.

law of nature that states that energy can neither be created nor destroyed, and thus the total energy in an isolated system remains constant; all the energy lost by one system must be gained by the surroundings or another system.

a condition where the temperatures are the same and heat no longer flows from one material to another.

the quantity of energy, usually measured in J/(g·°C), it takes per gram of a certain material to raise the temperature by one degree Celsius.

the flow of heat energy through the direct contact of matter.

 a material that conducts heat easily.

 a material that resists the flow of heat.

conversion of the organization of molecules in a substance without changing the individual molecules themselves, such as changing from solid to liquid or liquid to gas.

the temperature at which a substance changes phase from solid to liquid; for example, the melting point of water is 0°C.

 the energy required to change the phase of one gram of a material from liquid to gas or gas to liquid at constant temperature and constant pressure at the boiling point.

the temperature at which a substance changes phase from liquid to gas

 the energy required to change the phase of one gram of a material from liquid to solid or solid to liquid at constant temperature and constant pressure at the melting point.

a phase change from liquid to gas at a temperature below the boiling point.

a phase change from gas to liquid; a substance in its gas phase may condense at a temperature below its boiling point.

 thermal energy that is absorbed or released by a phase change.

the temperature and pressure at which the solid, liquid, and gas phases of a substance can all exist in equilibrium together.

the actual partial pressure of water vapor in air divided by the saturation vapor pressure at the same temperature.

the temperature at which air is saturated with H2O vapor (Rh = 100%).