This question tests understanding of how changes in thermal energy cause substances to change state by affecting particle motion. State changes are driven by thermal energy changes: adding thermal energy (heating) makes particles move faster, which can cause transitions toward gas state—solid + heat → liquid (melting, like ice → water) because particles vibrate so vigorously they break from fixed positions and start sliding, and liquid + heat → gas (boiling/evaporating, like water → steam) because particles move so fast they overcome attractions and separate into space. Removing thermal energy (cooling) makes particles slow down, causing transitions toward solid state—gas - heat → liquid (condensing, like steam → water) because slowing particles are pulled closer by attractions, and liquid - heat → solid (freezing, like water → ice) because particles move slowly enough to lock into fixed positions. For boiling: When liquid water is heated to 100°C (boiling point at normal pressure), continued addition of thermal energy causes particles to move so rapidly that they completely overcome the attractions to neighboring particles and escape into the air as gas (steam or water vapor)—this is called boiling, the liquid → gas transition that occurs at the boiling point temperature when thermal energy input gives particles enough kinetic energy to break free from the liquid. Choice A is correct because it correctly names the process: evaporating for liquid→gas below boiling point, where thermal energy addition allows surface particles to escape. Choice C reverses the direction, incorrectly predicting freezing when thermal energy is added, when adding heat actually causes melting or boiling, not freezing. Remember the pattern for thermal energy and states: adding thermal energy always moves substances toward gas state (solid → liquid → gas) because particles speed up and overcome attractions, while removing thermal energy always moves toward solid state (gas → liquid → solid) because particles slow down and attractions become more effective at organizing them—you can never freeze something by heating it or boil something by cooling it, the direction is set by energy flow.

This question tests understanding of how changes in thermal energy cause substances to change state by affecting particle motion. State changes are driven by thermal energy changes: adding thermal energy (heating) makes particles move faster, which can cause transitions toward gas state—solid + heat → liquid (melting, like ice → water) because particles vibrate so vigorously they break from fixed positions and start sliding, and liquid + heat → gas (boiling/evaporating, like water → steam) because particles move so fast they overcome attractions and separate into space. Removing thermal energy (cooling) makes particles slow down, causing transitions toward solid state—gas - heat → liquid (condensing, like steam → water) because slowing particles are pulled closer by attractions, and liquid - heat → solid (freezing, like water → ice) because particles move slowly enough to lock into fixed positions. For condensing: When water vapor (gas) comes into contact with a cold surface like a cold glass or mirror, thermal energy transfers from the fast-moving gas particles to the cold surface, slowing the water vapor particles down—as they slow, the attractions between water molecules become strong enough to pull the particles together from widely separated (gas) to touching (liquid), forming water droplets on the surface in the process called condensation (gas → liquid when thermal energy is removed). Choice C is correct because it correctly names the process: condensing for gas→liquid, and properly explains that thermal energy change affects particle motion which causes state change. Choice A reverses the direction, incorrectly predicting boiling when thermal energy is removed, when removing heat causes freezing or condensing, not boiling. Remember the pattern for thermal energy and states: adding thermal energy always moves substances toward gas state (solid → liquid → gas) because particles speed up and overcome attractions, while removing thermal energy always moves toward solid state (gas → liquid → solid) because particles slow down and attractions become more effective at organizing them—you can never freeze something by heating it or boil something by cooling it, the direction is set by energy flow.

This question tests understanding of how changes in thermal energy cause substances to change state by affecting particle motion. State changes are driven by thermal energy changes: adding thermal energy (heating) makes particles move faster, which can cause transitions toward gas state—solid + heat → liquid (melting, like ice → water) because particles vibrate so vigorously they break from fixed positions and start sliding, and liquid + heat → gas (boiling/evaporating, like water → steam) because particles move so fast they overcome attractions and separate into space. Removing thermal energy (cooling) makes particles slow down, causing transitions toward solid state—gas - heat → liquid (condensing, like steam → water) because slowing particles are pulled closer by attractions, and liquid - heat → solid (freezing, like water → ice) because particles move slowly enough to lock into fixed positions. For condensing: When water vapor (gas) comes into contact with a cold surface like a cold glass or mirror, thermal energy transfers from the fast-moving gas particles to the cold surface, slowing the water vapor particles down—as they slow, the attractions between water molecules become strong enough to pull the particles together from widely separated (gas) to touching (liquid), forming water droplets on the surface in the process called condensation (gas → liquid when thermal energy is removed). Choice B is correct because it identifies correct final state based on thermal energy direction, as removing heat from gas leads to liquid via condensing. Choice D predicts the wrong final state: claims liquid water boils into more gas, but cooling does not cause boiling. Remember the pattern for thermal energy and states: adding thermal energy always moves substances toward gas state (solid → liquid → gas) because particles speed up and overcome attractions, while removing thermal energy always moves toward solid state (gas → liquid → solid) because particles slow down and attractions become more effective at organizing them—you can never freeze something by heating it or boil something by cooling it, the direction is set by energy flow.

This question tests understanding of how changes in thermal energy cause substances to change state by affecting particle motion. State changes are driven by thermal energy changes: adding thermal energy (heating) makes particles move faster, which can cause transitions toward gas state—solid + heat → liquid (melting, like ice → water) because particles vibrate so vigorously they break from fixed positions and start sliding, and liquid + heat → gas (boiling/evaporating, like water → steam) because particles move so fast they overcome attractions and separate into space. Removing thermal energy (cooling) makes particles slow down, causing transitions toward solid state—gas - heat → liquid (condensing, like steam → water) because slowing particles are pulled closer by attractions, and liquid - heat → solid (freezing, like water → ice) because particles move slowly enough to lock into fixed positions. For melting: When thermal energy is added to ice (solid water at or below 0°C), the particles gain energy and vibrate more and more vigorously until at 0°C they have enough energy to break free from their fixed positions in the crystal pattern—at this point, melting occurs and ice transitions to liquid water as particles begin sliding past each other instead of vibrating in place. Choice C is correct because it accurately predicts the state change direction: adding heat moves toward gas, specifically melting for solid→liquid, and properly explains that thermal energy change affects particle motion which causes state change. Choice B reverses the direction, incorrectly predicting freezing when thermal energy is added, when adding heat actually causes melting or boiling, not freezing. Remember the pattern for thermal energy and states: adding thermal energy always moves substances toward gas state (solid → liquid → gas) because particles speed up and overcome attractions, while removing thermal energy always moves toward solid state (gas → liquid → solid) because particles slow down and attractions become more effective at organizing them—you can never freeze something by heating it or boil something by cooling it, the direction is set by energy flow.

This question tests understanding of how changes in thermal energy cause substances to change state by affecting particle motion. State changes are driven by thermal energy changes: adding thermal energy (heating) makes particles move faster, which can cause transitions toward gas state—solid + heat → liquid (melting, like ice → water) because particles vibrate so vigorously they break from fixed positions and start sliding, and liquid + heat → gas (boiling/evaporating, like water → steam) because particles move so fast they overcome attractions and separate into space. Removing thermal energy (cooling) makes particles slow down, causing transitions toward solid state—gas - heat → liquid (condensing, like steam → water) because slowing particles are pulled closer by attractions, and liquid - heat → solid (freezing, like water → ice) because particles move slowly enough to lock into fixed positions. For melting: When thermal energy is added to ice (solid water at or below 0°C), the particles gain energy and vibrate more and more vigorously until at 0°C they have enough energy to break free from their fixed positions in the crystal pattern—at this point, melting occurs and ice transitions to liquid water as particles begin sliding past each other instead of vibrating in place. Choice C is correct because it correctly names the process: melting for solid→liquid, where temperature stays constant during the state change as energy goes into breaking attractions. Choice A reverses the direction, incorrectly predicting freezing when thermal energy is added, when adding heat actually causes melting or boiling, not freezing. Remember the pattern for thermal energy and states: adding thermal energy always moves substances toward gas state (solid → liquid → gas) because particles speed up and overcome attractions, while removing thermal energy always moves toward solid state (gas → liquid → solid) because particles slow down and attractions become more effective at organizing them—you can never freeze something by heating it or boil something by cooling it, the direction is set by energy flow.

This question tests understanding of how changes in thermal energy cause substances to change state by affecting particle motion. State changes are driven by thermal energy changes: adding thermal energy (heating) makes particles move faster, which can cause transitions toward gas state—solid + heat → liquid (melting, like ice → water) because particles vibrate so vigorously they break from fixed positions and start sliding, and liquid + heat → gas (boiling/evaporating, like water → steam) because particles move so fast they overcome attractions and separate into space. Removing thermal energy (cooling) makes particles slow down, causing transitions toward solid state—gas - heat → liquid (condensing, like steam → water) because slowing particles are pulled closer by attractions, and liquid - heat → solid (freezing, like water → ice) because particles move slowly enough to lock into fixed positions. For boiling: When liquid water is heated to 100°C (boiling point at normal pressure), continued addition of thermal energy causes particles to move so rapidly that they completely overcome the attractions to neighboring particles and escape into the air as gas (steam or water vapor)—this is called boiling, the liquid → gas transition that occurs at the boiling point temperature when thermal energy input gives particles enough kinetic energy to break free from the liquid. Choice B is correct because it accurately predicts the state change direction: adding heat moves toward gas, specifically boiling for liquid→gas at 100°C. Choice A reverses the direction, incorrectly predicting the water will freeze into ice when thermal energy is added, when adding heat actually causes melting or boiling, not freezing. Remember the pattern for thermal energy and states: adding thermal energy always moves substances toward gas state (solid → liquid → gas) because particles speed up and overcome attractions, while removing thermal energy always moves toward solid state (gas → liquid → solid) because particles slow down and attractions become more effective at organizing them—you can never freeze something by heating it or boil something by cooling it, the direction is set by energy flow.

This question tests understanding of how changes in thermal energy cause substances to change state by affecting particle motion. State changes are driven by thermal energy changes: adding thermal energy (heating) makes particles move faster, which can cause transitions toward gas state—solid + heat → liquid (melting, like ice → water) because particles vibrate so vigorously they break from fixed positions and start sliding, and liquid + heat → gas (boiling/evaporating, like water → steam) because particles move so fast they overcome attractions and separate into space. Removing thermal energy (cooling) makes particles slow down, causing transitions toward solid state—gas - heat → liquid (condensing, like steam → water) because slowing particles are pulled closer by attractions, and liquid - heat → solid (freezing, like water → ice) because particles move slowly enough to lock into fixed positions. For freezing: Placing liquid water in a freezer removes thermal energy, causing the water molecules to slow down—when temperature reaches 0°C, the particles are moving slowly enough that the attractions between molecules can pull them into fixed positions forming a crystal pattern (ice structure), and the water freezes solid as particles transition from sliding past each other to vibrating in locked positions. Choice C is correct because it identifies correct final state based on thermal energy direction, as removing heat from liquid below 0°C leads to solid ice. Choice A predicts the wrong final state: claims water vapor (gas), but cooling moves toward solid, not gas. Remember the pattern for thermal energy and states: adding thermal energy always moves substances toward gas state (solid → liquid → gas) because particles speed up and overcome attractions, while removing thermal energy always moves toward solid state (gas → liquid → solid) because particles slow down and attractions become more effective at organizing them—you can never freeze something by heating it or boil something by cooling it, the direction is set by energy flow.

This question tests understanding of how changes in thermal energy cause substances to change state by affecting particle motion. State changes are driven by thermal energy changes: adding thermal energy (heating) makes particles move faster, which can cause transitions toward gas state—solid + heat → liquid (melting, like ice → water) because particles vibrate so vigorously they break from fixed positions and start sliding, and liquid + heat → gas (boiling/evaporating, like water → steam) because particles move so fast they overcome attractions and separate into space. Removing thermal energy (cooling) makes particles slow down, causing transitions toward solid state—gas - heat → liquid (condensing, like steam → water) because slowing particles are pulled closer by attractions, and liquid - heat → solid (freezing, like water → ice) because particles move slowly enough to lock into fixed positions. For boiling: When liquid water is heated to 100°C (boiling point at normal pressure), continued addition of thermal energy causes particles to move so rapidly that they completely overcome the attractions to neighboring particles and escape into the air as gas (steam or water vapor)—this is called boiling, the liquid → gas transition that occurs at the boiling point temperature when thermal energy input gives particles enough kinetic energy to break free from the liquid. Choice B is correct because it accurately predicts the state change direction: adding heat moves toward gas, correctly names the process as boiling for liquid→gas, and identifies correct final state based on thermal energy direction. Choice A reverses the direction, incorrectly predicting freezing when thermal energy is added, when adding heat actually causes melting or boiling, not freezing. Remember the pattern for thermal energy and states: adding thermal energy always moves substances toward gas state (solid → liquid → gas) because particles speed up and overcome attractions, while removing thermal energy always moves toward solid state (gas → liquid → solid) because particles slow down and attractions become more effective at organizing them—you can never freeze something by heating it or boil something by cooling it, the direction is set by energy flow.

This question tests understanding of how changes in thermal energy cause substances to change state by affecting particle motion. State changes are driven by thermal energy changes: adding thermal energy (heating) makes particles move faster, which can cause transitions toward gas state—solid + heat → liquid (melting, like ice → water) because particles vibrate so vigorously they break from fixed positions and start sliding, and liquid + heat → gas (boiling/evaporating, like water → steam) because particles move so fast they overcome attractions and separate into space. Removing thermal energy (cooling) makes particles slow down, causing transitions toward solid state—gas - heat → liquid (condensing, like steam → water) because slowing particles are pulled closer by attractions, and liquid - heat → solid (freezing, like water → ice) because particles move slowly enough to lock into fixed positions. For condensing: When water vapor (gas) comes into contact with a cold surface like a cold glass or mirror, thermal energy transfers from the fast-moving gas particles to the cold surface, slowing the water vapor particles down—as they slow, the attractions between water molecules become strong enough to pull the particles together from widely separated (gas) to touching (liquid), forming water droplets on the surface in the process called condensation (gas → liquid when thermal energy is removed). Choice A is correct because it accurately predicts the state change direction: removing heat moves toward solid, correctly names the process as condensing for gas→liquid, and properly explains that thermal energy change affects particle motion which causes state change. Choice B reverses the direction, incorrectly predicting boiling when thermal energy is removed, when removing heat causes freezing or condensing, not boiling. Remember the pattern for thermal energy and states: adding thermal energy always moves substances toward gas state (solid → liquid → gas) because particles speed up and overcome attractions, while removing thermal energy always moves toward solid state (gas → liquid → solid) because particles slow down and attractions become more effective at organizing them—you can never freeze something by heating it or boil something by cooling it, the direction is set by energy flow.

This question tests understanding of how changes in thermal energy cause substances to change state by affecting particle motion. State changes are driven by thermal energy changes: adding thermal energy (heating) makes particles move faster, which can cause transitions toward gas state—solid + heat → liquid (melting, like ice → water) because particles vibrate so vigorously they break from fixed positions and start sliding, and liquid + heat → gas (boiling/evaporating, like water → steam) because particles move so fast they overcome attractions and separate into space. Removing thermal energy (cooling) makes particles slow down, causing transitions toward solid state—gas - heat → liquid (condensing, like steam → water) because slowing particles are pulled closer by attractions, and liquid - heat → solid (freezing, like water → ice) because particles move slowly enough to lock into fixed positions. For melting: When thermal energy is added to ice (solid water at or below 0°C), the particles gain energy and vibrate more and more vigorously until at 0°C they have enough energy to break free from their fixed positions in the crystal pattern—at this point, melting occurs and ice transitions to liquid water as particles begin sliding past each other instead of vibrating in place. Choice B is correct because it accurately predicts the state change direction: adding heat moves toward gas, correctly names the process as melting for solid→liquid, and properly explains that thermal energy change affects particle motion which causes state change. Choice A reverses the direction, incorrectly predicting freezing when thermal energy is added, when adding heat actually causes melting or boiling, not freezing. Remember the pattern for thermal energy and states: adding thermal energy always moves substances toward gas state (solid → liquid → gas) because particles speed up and overcome attractions, while removing thermal energy always moves toward solid state (gas → liquid → solid) because particles slow down and attractions become more effective at organizing them—you can never freeze something by heating it or boil something by cooling it, the direction is set by energy flow.