Domain: Natural Science — Chemistry
Target concept: Reaction between concentrated sulfuric acid and copper

Video generation prompt: A copper sheet is placed in a test tube, concentrated sulfuric acid is added, and the mixture is heated with an alcohol lamp.

Evaluation guide:
(i) Target concept: Oxidation-reduction reaction where hot concentrated sulfuric acid acts as oxidizing agent on copper metal, producing copper(II) sulfate, sulfur dioxide, and water.
Minimum mechanism: Thermal activation is required to overcome kinetic barrier; reaction does not proceed at room temperature; SO2 formation requires both oxidation of S(VI) to S(IV) and reduction of Cu(0) to Cu(II); aqueous Cu2+ complexation yields blue-green color; SO2 hydration in ambient moisture produces visible sulfurous acid mist (white fumes).
(ii)Storyline: Frame 0–2: Static scene: empty test tube, copper sheet held above opening. Frame 3–4: Copper sheet inserted fully into tube and released. Frame 5–6: Concentrated H2SO4 poured into tube, covering copper. Frame 7–8: Alcohol lamp flame appears and contacts tube base. Frame 9–10: Dissolution initiates at copper-acid interface; blue-green tint emerges; white fumes rise continuously. Perspective: Fixed frontal close-up (tube occupies ≥70% height), full tube visible from rim to base, no hand occlusion after placement, lighting reveals meniscus and fume column.

Manual:
Experimental Procedure
1. Place a clean copper sheet into a dry test tube.
2. Carefully add ~2 mL concentrated sulfuric acid to the test tube so it covers the copper sheet.
3. Heat the bottom of the test tube evenly with an alcohol lamp flame for ~10 seconds.
Observation of Experimental Phenomena
- The reddish-brown copper sheet gradually dissolves.
- The colorless acid solution turns blue-green.
- Dense white fumes (SO2 gas) rise from the solution surface during heating.
Summary of Experimental Principles
Concentrated H2SO4 oxidizes Cu metal upon heating: Cu + 2H2SO4 → CuSO4 + SO2↑ + 2H2O. CuSO4 imparts blue-green color; SO2 is pungent, colorless gas forming visible white fumes in moist air.

Prompt Grounding rubric:
level_1: None of the four required items appear together: no copper sheet, no test tube, no concentrated sulfuric acid poured in, and no alcohol lamp flame heating the tube.
level_2: Some items appear, but at least three of the four are missing or wrong: for example the metal shown isn't copper-colored, the liquid looks like plain water instead of concentrated sulfuric acid, a Bunsen burner or other flame source stands in for the alcohol lamp, or no test tube is used at all.
level_3: A reddish-brown copper sheet, a vertical test tube, a colorless-to-pale liquid consistent with concentrated sulfuric acid inside the tube, and an alcohol lamp with a flame beneath the tube are all present and identifiable, but one action is out of place, such as the copper being placed in after the acid, the acid added before the copper, or the flame never actually touching the tube's base.
level_4: Everything in score 3 holds, and the three actions happen in the right order and place: the copper sheet goes into the empty tube first, the acid is then poured onto the copper inside that same tube, and the alcohol lamp's flame is applied to the tube's base, with no swapped materials and no copper sitting outside the tube while acid is inside. One small flaw is still allowed, like the tube tilting slightly during the pour or the flame flickering while still staying under the tube.
level_5: Everything in score 4 holds, and every detail matches: the copper sheet looks reddish-brown and metallic, the test tube is clear glass with a rounded bottom, the acid is a still, colorless-to-faint-amber liquid filling less than a third of the tube, the alcohol lamp's flame burns steadily with a blue-tinted core directly under the tube's lower third, and the three actions (insert copper, pour acid onto it, apply flame) happen in that exact order with no object moved out of place, no swapped materials, and nothing blocking the view.

Scientific and Causal Correctness rubric:
level_1: The copper sheet stays exactly as it looked at the start (same shape, same reddish color, same size) for the entire clip, the liquid never changes color or produces gas, and nothing about the tube's contents changes despite the heating.
level_2: The copper sheet still looks intact and unchanged, the liquid stays colorless and still, and there is no gas, fumes, darkening, or any hint of the blue-green color that should appear. Nothing in the tube changes state at any point.
level_3: The copper sheet visibly shrinks at least at one edge or corner, the liquid takes on a faint blue-green tint (not a strong pure blue, not yellow), and faint white fumes appear above the liquid only once heating has started, with no black coating forming on the copper, no violent bubbling or splashing, and the copper shrinking steadily from the point where it touches the acid.
level_4: Everything in score 3 holds, and the sequence tracks the heating correctly: the copper shrinks only after the flame touches the tube, the liquid moves from colorless to pale blue to a clearer blue-green as the copper dissolves, and dense white fumes rise steadily from the surface only while the flame is applied, with no black or brown residue and no leftover copper flecks floating free. A small imperfection is allowed, such as the fumes looking a bit thicker than expected or the blue-green shade being slightly off.
level_5: The copper sheet dissolves completely with no leftover fragments or stains on the tube walls, the solution ends up a clear, even blue-green throughout, the white fumes rise continuously in the air space above the liquid without condensing on the tube walls, the fuming starts right as the flame is applied and dies down again soon after the flame is pulled away, and there's no blackening, no yellow sulfur deposit, and no bubbling unrelated to the gas being produced.

Spatiotemporal Consistency rubric:
level_1: The test tube jumps to a different spot or angle between frames, the copper sheet blinks in or out of existence, the flame appears to leap from the lamp onto the tube with no visible connection between them, the liquid level jumps suddenly (say, from full to half in a single frame), a sudden lighting change hides the tube and lamp, or the tube appears to bend or crack for no physical reason.
level_2: One clear break in continuity happens: the copper sheet is inside the tube in one frame and outside it in the next with no path shown getting it there, the flame appears to originate from inside the test tube itself, liquid sprays upward in a way that ignores gravity, the tube rotates more than about 45 degrees with no hand or stand supporting it, or the background swaps to a visibly different scene between shots.
level_3: The copper sheet stays inside the test tube the whole time, the flame stays continuously under the tube's base, the liquid surface stays flat and level aside from gentle ripples from the heat, nothing in the shot vanishes, reappears, or suddenly changes size, and the camera holds one steady, front-on view showing the full length of the tube and the lamp beneath it.
level_4: Everything in score 3 holds, and the copper stays fully inside the tube with no part poking out, the flame stays centered under the tube's bottom, the liquid surface stays parallel to the ground, and the fumes rise straight up inside the tube's air space; the copper's dissolving, the fume buildup, and the color change all progress gradually rather than jumping between stages. One small flaw is allowed, like a brief lens flare covering a sliver of the tube's top or a couple of frames of motion blur during the pour that don't hide the copper or the liquid level.
level_5: Nothing in the shot breaks physical continuity: the copper sheet only moves by settling into place when first put in, then stays put until it starts dissolving; the flame stays the same size and position under the tube for the whole clip; the liquid's surface only ever changes shape gradually from the heat, never suddenly bulging or rippling oddly; the fumes rise as one smooth, unbroken column filling roughly the center of the tube's air space; and the tube, flame, and liquid all stay sharply in focus and evenly lit with no flickering, no sudden zoom-like shifts, and no color fringing around the edges of objects.