Changes in Temperature

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Molecule Noun

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[mol-uh-kyool]

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Molecule

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A tiny particle made of two or more atoms, where the total number of molecules affects a substance's thermal energy.

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Example: This image shows a water molecule, with two hydrogen atoms and one oxygen atom, illustrating how molecules are made of atoms.

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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 an object or particle has because of its motion, which is directly related to the movement of molecules.

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

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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 in a substance, which indicates 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.

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Thermal Energy Noun

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[thur-muhl en-er-jee]

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Thermal Energy

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The total kinetic energy of all the molecules that make up a substance, depending on its temperature and number of molecules.

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Example: Molecules in a hot area move faster, transferring thermal energy to a cooler area.

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Heat Noun

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[heet]

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Heat

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The transfer of thermal energy from a hotter object to a colder one due to a difference in their temperatures.

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Example: Heat moves from the hot side to the cold side, shown by arrows.

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System Noun

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[sis-tuhm]

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System

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A collection of interacting objects or parts that form a complex whole where total energy is conserved during transfers.

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Example: Heating water shows energy transfer as temperature rises from freezing to boiling.

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Energy Transfer Noun

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[en-er-jee trans-fur]

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Energy Transfer

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The movement of energy from one object or system to another, such as thermal energy moving to a cooler object.

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Example: Heat flows from a hot object to a cold one, showing energy transfer.

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Equilibrium Noun

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[ee-kwuh-lib-ree-uhm]

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Equilibrium

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The state where a system is balanced and there is no net change, such as when objects reach the same temperature.

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Example: A balanced scale shows equilibrium, like when two objects reach the same temperature.

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Collision Noun

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[kuh-lizh-uhn]

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Collision

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An event where particles bump into each other, which is the primary way thermal energy is transferred between molecules.

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Example: Particles colliding to transfer thermal energy between them.

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Conservation of Energy Noun

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[kon-ser-vey-shuhn uhv en-er-jee]

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Conservation of Energy

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The principle that energy cannot be created or destroyed, only moved from one part of a system to another.

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Example: Pulling back one ball transfers energy through the others, demonstrating energy conservation.