Domain: Natural Science — Earth Science
Target concept: Heating hydrated copper sulfate crystals leads to dehydration and a change in mineral color.

Video generation prompt: Heat bright blue copper(II) sulfate hydrate crystals in a shallow porcelain dish using a steady Bunsen flame.

Evaluation guide:
(i) Target concept: Thermal dehydration of a hydrated salt causes reversible color change due to loss of water ligands from the Cu²⁺ coordination sphere.
Minimum mechanism: Crystals must be solid-phase, stoichiometric CuSO₄·5H₂O; heating must be dry and sub-decomposition (no oxidation); color change requires intact [Cu(H₂O)₄]²⁺ octahedral complex (blue) converting to distorted [Cu]²⁺ site in anhydrous lattice (white).
(ii)Storyline: Frame 1–2: Static shot showing shallow porcelain dish centered, filled with bright blue crystalline granules. Frame 3–4: Steady Bunsen flame appears adjacent to dish base, maintaining fixed spatial relationship. Frame 5–7: Blue crystals visibly and uniformly desaturate → lighten → become pale white, progressing from bottom (heat-affected zone) upward; no fluid phase emerges. Frame 8–10: Final state shows only dry, matte white powder in same dish, flame still present and stable; no condensate, residue, or secondary reactions. Perspective: Fixed frontal/oblique overhead view, no camera movement, full dish and flame in frame at all times; lighting consistent, no occlusion.

Manual:
Experimental Procedure
1. Place bright blue copper(II) sulfate hydrate crystals in a shallow porcelain dish.
2. Position dish over a steady Bunsen burner flame.
3. Heat gently until color change completes.
Observation of Experimental Phenomena
Bright blue crystals gradually turn uniform pale white while remaining solid and dry; no melting, bubbling, or steam observed.
Summary of Experimental Principles
Heating hydrated copper sulfate crystals drives off water of crystallization, forming anhydrous copper(II) sulfate, which is white — demonstrating dehydration-induced color change in minerals.

Prompt Grounding rubric:
level_1: No shallow porcelain dish present; no copper(II) sulfate hydrate crystals visible; no Bunsen burner or flame visible; no heating action depicted; none of the required objects or actions from the posted_prompt appear.
level_2: At least one required object is present (e.g., dish OR crystals OR flame), but no coherent heating setup exists; crystals not placed in dish; flame not directed at dish; no visible contact between flame and dish; sequence of placement/heating is absent or reversed.
level_3: Shallow porcelain dish is present and contains bright blue copper(II) sulfate hydrate crystals; a Bunsen flame is visible and positioned adjacent to the dish; flame is steady (no flickering extinction or erratic motion); crystals are stationary inside dish during heating; all three core objects (dish, crystals, flame) are present and spatially related as required.
level_4: All conditions for score 3 are satisfied, AND the flame maintains consistent spatial adjacency to the dish throughout the video; crystals remain fully within the dish boundaries (no spillage, levitation, or displacement); dish remains stationary on surface; no extraneous objects (e.g., tongs, labels, hands) enter frame or occlude the core setup.
level_5: All conditions for score 4 are satisfied, AND the shallow porcelain dish is clearly identifiable as shallow (i.e., low depth-to-diameter ratio, rim visible above crystal layer); crystals are unambiguously bright blue (not green, purple, grey, or desaturated); flame is yellow-blue conical Bunsen flame (not candle-like, torch-like, or diffuse glow); no visual artifacts, overlays, or compositional distractions: only the dish, crystals, and flame in fixed viewpoint.

Scientific and Causal Correctness rubric:
level_1: No color change observed; crystals remain bright blue throughout; no whitening, fading, or discoloration occurs; no state change visible; no causal link between heating and appearance change is depicted.
level_2: Color change occurs but is incorrect: e.g., crystals turn black, green, brown, or transparent; or color change happens before flame contact or without flame presence; or crystals vanish/melt/liquefy instead of dehydrating to white powder.
level_3: Crystals begin as bright blue and transition to a visibly different solid state (specifically, a uniform pale white or off-white color) with no intermediate liquid phase; color change occurs only while flame is adjacent to dish; change is progressive (not instantaneous jump) and confined to crystals (not dish or background).
level_4: All conditions for score 3 are satisfied, AND the white product retains granular/crystalline solid texture (no melting, bubbling, charring, or clumping into paste); color contrast between initial bright blue and final white is high and unambiguous; no rehydration or condensation effects appear (e.g., no droplets, steam, or mist).
level_5: All conditions for score 4 are satisfied, AND the final white state is matte, dry, and powdery (not glossy, wet, or translucent); the blue-to-white transition is continuous and spatially co-located (same crystal regions darken then whiten, not patchy or striped); no residual blue specks remain in final state; no thermal decomposition side-effects (e.g., blackening at edges, smoke, odor cues implied visually).

Spatiotemporal Consistency rubric:
level_1: Severe spatiotemporal rupture: dish teleports between frames; crystals vanish/reappear; flame jumps discontinuously; lighting changes abruptly (e.g., full shadow → full highlight mid-video); dish rotates or flips; structural integrity breaks (e.g., dish bends, cracks, or dissolves).
level_2: Multiple moderate violations: dish wobbles violently or shifts position >1x its width; crystals visibly slide/spill out of dish; flame flickers so intensely that its presence becomes intermittent (off >1/3 of frames); shadows or highlights shift direction inconsistently across frames; camera zooms or pans.
level_3: Minor but detectable motion artifacts: dish exhibits slight tremor (<0.5x dish width amplitude); crystals show minor settling but remain fully inside dish; flame has gentle, natural flicker (no extinction or flare-up); lighting and shadow orientation remain fixed; no object deformation, clipping, or occlusion by frame edge.
level_4: All conditions for score 3 are satisfied, AND motion is smooth and physically plausible: flame heat shimmer is subtle but continuous above dish; no inter-frame jitter or strobing; dish surface reflects ambient light consistently; no temporal mismatch (e.g., flame appears after color change begins).
level_5: All conditions for score 4 are satisfied, AND zero perceptual discontinuities: no aliasing, no motion blur inconsistent with speed, no frame duplication or drop; heat distortion above dish is faint, localized, and evolves continuously; dish rim, crystal edges, and flame cone maintain crisp, stable definition across all frames; no parallax shift or perspective warp.