Investigating Energy and Phase Change

Front

Molecule Noun

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[mol-i-kyool]

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Molecule

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A group of atoms bonded together, representing the smallest unit of a chemical compound that can participate in a reaction.

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Example: A water molecule is made of two hydrogen atoms bonded to one oxygen atom.

Front

Phase Noun

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[fayz]

Back

Phase

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A distinct form of matter, such as a solid, liquid, or gas, characterized by its molecular arrangement and movement.

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Example: Shows how molecules are arranged in solid, liquid, and gas phases.

Front

Kinetic Energy Noun

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

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Kinetic Energy

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The energy that a substance's molecules possess due to their constant motion, which increases as temperature rises.

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Example: The swinging balls in Newton's cradle show kinetic energy as they move.

Front

Temperature Noun

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[tem-per-uh-cher]

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Temperature

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A measure of the average kinetic energy of the molecules within a substance, indicating how hot or cold it is.

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Example: Molecules in a hot area move faster than in a cold area, showing temperature differences.

Front

Total Thermal Energy Noun

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[toh-tl thur-muhl en-er-jee]

Back

Total Thermal Energy

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The sum of the kinetic and potential energy of all the molecules that make up a system or substance.

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Example: Particles in a hot area move faster, showing thermal energy transfer to a cooler area.

Front

Evaporation Noun

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[i-vap-uh-rey-shuhn]

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Evaporation

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The phase change process during which a substance in a liquid state changes to a gaseous state at the surface.

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Example: The sun heats a puddle, causing the water to evaporate into the air.

Front

Condensation Noun

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[kon-den-sey-shuhn]

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Condensation

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The phase change process during which a substance in a gaseous state changes to a liquid state upon cooling.

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Example: Warm moist air hits a cold surface, turning into liquid droplets, showing condensation.

Front

Crystallization Noun

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[kris-tuh-luh-zey-shuhn]

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Crystallization

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The process by which a solid forms, where atoms or molecules are highly organized into a structured crystal lattice.

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Example: The image shows a crystal lattice of NaCl, demonstrating how atoms are organized in crystallization.

Front

Precipitation Noun

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[pri-sip-i-tey-shuhn]

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Precipitation

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Any form of water, such as rain, snow, sleet, or hail, that condenses in the atmosphere and falls.

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Example: Clouds releasing rain and snow show how precipitation occurs.

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Combustion Noun

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[kuhm-buhs-chuhn]

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Combustion

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A rapid chemical reaction between a substance and an oxidant, usually oxygen, that produces heat and light.

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Example: Combustion is shown as a reaction where a hydrocarbon and oxygen produce carbon dioxide, water, heat, and light.