Domain: Natural Science — Physics
Target concept: The solution temperature decreases significantly during the dissolution of ammonium nitrate, indicating heat absorption.

Video generation prompt: Through a small resealable opening in its lid, add ammonium nitrate to a closed container that holds water and a thermometer, then reseal it and dissolve the solid in the water, observing the change in the thermometer reading.

Evaluation guide:
(i) Target concept: Endothermic dissolution of an ionic solid in water.
Minimum mechanism: Solid-phase ammonium nitrate must dissociate into hydrated NH₄⁺ and NO₃⁻ ions, requiring net energy input from solvent thermal energy, resulting in bulk temperature drop detectable by immersed thermometer.
(ii)Storyline: Frame sequence must show: (A) Initial state: intact closed container, water inside, thermometer bulb fully immersed and stable reading; (B) Action phase: the container's resealable lid opening is used to introduce the solid, which moves toward the water surface; (C) Contact phase: solid touches water surface and begins immediate dispersion; (D) Dissolution phase: solid visibly diminishes uniformly while thermometer column descends steadily; (E) Final state: no solid residue, clear solution, lowered thermometer reading. All under fixed viewpoint, no occlusion, full visibility of thermometer scale and container interior.

Manual:
1. Place a clear closed container (e.g., a glass vial with a resealable lid) filled with water and containing a fully immersed thermometer.
2. Briefly open the resealable lid to add white crystalline ammonium nitrate solid into the container so it contacts the water, then reseal the container.
3. Observe the thermometer reading decrease continuously.
Observation: Thermometer reading drops after solid contacts water; solid disappears as it dissolves; water remains clear and colorless.
Principle: Dissolution of ammonium nitrate absorbs heat from surroundings, causing measurable temperature decrease.

Prompt Grounding rubric:
level_1: No container is shown at all, or there is no thermometer, no ammonium nitrate solid, or no water; the objects named in the prompt do not all appear together, and no dissolution setup is depicted.
level_2: At least one required object shows up (the container, the thermometer, or the white crystalline solid) but not all of them together; for example, the solid is poured into an open beaker with no lid at all, or there is no enclosure resembling the resealable closed container described.
level_3: A container with a resealable lid, a thermometer, water, and white crystalline ammonium nitrate solid are all visible in the same fixed shot; the solid is shown being introduced into the container (for instance, through the lid's opening) so that it can reach the water inside.
level_4: All the level-3 requirements are met, and beyond that: the solid is shown making direct contact with the water; the thermometer bulb stays fully immersed and does not move throughout; nothing extraneous (a lingering hand, a label, an unrelated tool) blocks the view of the container, thermometer, or solid; and the container, thermometer, and solid keep the spatial arrangement described (container holding water and thermometer, solid entering from above before contact).
level_5: All the level-4 requirements are met, and beyond that: the sequence follows this order without skipping or reversing steps. The container, already holding water and the thermometer, is shown first; then the solid is introduced through the resealable opening; then the solid touches the water; the solid's appearance (white, crystalline) stays the same throughout apart from dissolving; and the container, thermometer, and solid never inexplicably appear or disappear between frames.

Scientific and Causal Correctness rubric:
level_1: The thermometer reading rises or stays flat; there is no visible temperature change at all; the solid appears to release heat as it dissolves (steam or condensation forming, a warm-looking glow); the water's color or clarity changes for reasons unrelated to the solid dissolving; or there is no causal connection between adding the solid and how the thermometer behaves.
level_2: The thermometer reading does change, but in the wrong direction (it rises) or inconsistently (it drops, then rises back); the solid vanishes with no visible dissolving process; the water looks the same before and after even though the solid is gone; or there is no visible correlation between the solid touching the water and the thermometer's response.
level_3: The thermometer reading drops after the solid touches the water; the solid visibly shrinks or disappears while submerged; the water stays clear and colorless throughout; and the drop in reading only begins once the solid has actually contacted the water: solid added, then contact, then dissolving, then the temperature falls.
level_4: All the level-3 requirements are met, and beyond that: the thermometer trends downward continuously from the moment of contact, with no rise or flat plateau along the way; every crystal of the solid is fully dissolved by the end, with none left floating or settled at the bottom; and there is no bubbling, gas release, or layer separation that would contradict a simple endothermic dissolution.
level_5: All the level-4 requirements are met, and beyond that: the thermometer's column falls smoothly, without jumping or reversing; the solid is shown as distinct crystals before contact, then spreads evenly into solution rather than clumping together, sinking untouched, or dissolving only at the surface; and the water stays clear, uniform, and undisturbed except for the gentle motion implied by the solid dissolving, with no visual cue (bubbling, fizzing, a warm shimmer) suggesting heat is being released instead of absorbed.

Spatiotemporal Consistency rubric:
level_1: The container abruptly appears in a different spot or orientation between frames with no motion connecting the two states; the thermometer's position changes, or it disappears and reappears without ever moving there; the solid is suddenly inside the water with no visible path getting it there; the room's lighting suddenly switches as though a different light source took over; or the container visibly cracks, bends, or loses its seal for no reason.
level_2: At least one clear break in continuity shows up: the thermometer bulb is submerged in one frame but hovering in air in the next; the solid enters the container off-camera and shows up already underwater; the water level changes with no visible cause; the shadow cast by the container or thermometer swings to face a different way from one frame to the next; or background details flicker or distort.
level_3: The container stays in the same place and orientation; the thermometer stays upright and fully inside the container the whole time; the solid travels along a visible, unbroken path from outside the container down into the water; the water's surface stays calm, with no odd splashing or bobbing; and the shadow the container and thermometer cast keeps roughly the same size and placement, since nothing about the room's light source changes mid-scene.
level_4: All the level-3 requirements are met, and beyond that: the solid falls the way gravity would carry it, not floating or speeding up unnaturally; it never passes through the container's wall or lid; there is no sudden change in scale or camera perspective; and the solid's path from outside to submerged shows every intermediate position rather than jumping straight from above the surface to fully underwater.
level_5: All the level-4 requirements are met, and beyond that: the solid's descent shows an unbroken, gradual progression from entry to the bottom; the thermometer column's movement is gradual and steady, never jumping; the water shows small ripples only right when the solid first touches it, then settles flat; and the container, thermometer, and solid all keep clean, stable outlines throughout, with no visible tearing, warping, or flickering along their edges.