Describing Phase Change at Two Scales

Front

Phase Noun

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[fayz]

Back

Phase

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One of the distinct forms in which matter can exist, characterized by its physical properties and molecular arrangement.

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Example: The image shows solid, liquid, and gas phases with molecular arrangements, illustrating phase changes.

Front

Phase Change Noun

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[fayz chaynj]

Back

Phase Change

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A transition of a substance from one state of matter to another, involving changes in appearance and molecular movement.

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Example: The image shows how molecules are packed in solids, spread in liquids, and dispersed in gases, explaining phase changes.

Front

Solid Noun

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[sol-id]

Back

Solid

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A phase of matter that maintains a fixed shape and volume because its molecules are tightly packed and vibrate in place.

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Example: The image shows tightly packed molecules in a solid, explaining its fixed shape and volume.

Front

Liquid Noun

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[lik-wid]

Back

Liquid

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A phase of matter that has a definite volume but takes the shape of its container as its molecules can flow.

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Example: Water in a bucket shows how pressure varies with depth, demonstrating liquid properties.

Front

Gas Noun

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[gas]

Back

Gas

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A phase of matter with no fixed shape or volume, whose molecules move freely to fill any available space.

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Example: The image shows gases like air and helium, illustrating that gases have no fixed shape or volume.

Front

Molecule Noun

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[mol-uh-kyool]

Back

Molecule

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The smallest particle of a substance, made of two or more atoms bonded together, that has the properties of that substance.

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Example: A water molecule has two hydrogen atoms bonded to one oxygen atom, showing how atoms form molecules.

Front

Scale Noun

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[skayl]

Back

Scale

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The level or size at which phenomena are observed, ranging from the visible macroscale to the invisible molecular scale.

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Example: The image shows how different scales, from kilometers to picometers, relate to real-world examples like a human and DNA.

Front

Freedom of Movement Noun

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[free-duhm uv moov-muhnt]

Back

Freedom of Movement

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The ability of molecules within a substance to move relative to one another, which determines the substance's phase.

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Example: Molecules in solids are tightly packed, in liquids they move more freely, and in gases they move independently.

Front

Kinetic Energy Noun

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

Back

Kinetic Energy

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The energy an object or particle possesses due to its motion; it increases with speed and mass.

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Example: A cyclist speeds down a hill, gaining kinetic energy from motion.

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 atoms or molecules in a system, indicating its degree of hotness.

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Example: Molecules in hot and cold areas move differently, showing temperature differences.