Heat and Matter

Front

Matter Noun

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[mat-er]

Back

Matter

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Anything that possesses mass and takes up space, existing in states such as solid, liquid, or gas.

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Example: This image shows how the particles that make up matter are arranged differently in solids (tightly packed), liquids (close but random), and gases (far apart).

Front

Solid Noun

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[sol-id]

Back

Solid

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A state of matter characterized by tightly packed particles that vibrate in fixed positions, maintaining a definite shape and volume.

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Example: This shows how particles in a solid are packed tightly together in a fixed, repeating pattern, giving the solid a definite shape and volume.

Front

Liquid Noun

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[lik-wid]

Back

Liquid

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A state of matter where particles are free to flow over each other, taking the shape of their container.

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Example: This diagram shows that the particles in a liquid are close together but can move past one another, taking the shape of their container.

Front

Gas Noun

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[gas]

Back

Gas

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A state of matter in which particles are widely separated, move rapidly, and expand to fill any available volume.

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Example: This image shows that in a gas, particles are spread far apart from each other and move freely to fill the entire container.

Front

Kinetic Energy Noun

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[ki-net-ik en-er-jee]

Back

Kinetic Energy

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The energy that a body possesses by virtue of being in motion, which increases as particle speed increases.

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Example: A soccer ball flying through the air has kinetic energy because it is an object in motion.

Front

Thermal Energy Noun

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[thur-muhl en-er-jee]

Back

Thermal Energy

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The total kinetic and potential energy of all the particles that constitute a substance, related to its temperature.

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Example: This diagram shows that thermal energy is the motion of particles. The particles in the hot (red) area move faster than the particles in the cold (blue) area.

Front

Temperature Noun

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[tem-per-uh-cher]

Back

Temperature

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A measure of the average kinetic energy of the individual particles within an object or system.

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Example: This image shows a thermometer, a tool used to measure temperature by observing how much the liquid inside expands or contracts.

Front

Heat Noun

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[heet]

Back

Heat

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The transfer of thermal energy between objects or systems that are at different temperatures, flowing from warmer to cooler.

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Example: This diagram shows that heat is energy that flows from a hot object (the red block) to a cold object (the blue block).

Front

Thermal Equilibrium Noun

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[thur-muhl ee-kwi-lib-ree-uhm]

Back

Thermal Equilibrium

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The state reached when two objects in thermal contact stop exchanging heat because they have achieved the same temperature.

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Example: This image shows a hot object (100°) and a cold object (0°) exchanging heat over time until they both reach the same final temperature (50°).

Front

Physical Change Noun

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[fiz-i-kuhl cheynj]

Back

Physical Change

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A change affecting the form of a substance, such as its state or shape, without altering its chemical composition.

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Example: A solid substance (represented by packed particles) dissolves in a liquid, mixing the particles together without changing what they are, showing a physical change.