Domain: Engineering — Chemical Engineering
Target concept: Thermite reaction

Video generation prompt: Prepare an aluminothermic reaction mixture (aluminum powder : iron oxide = 1:3 by mass), load it into a refractory crucible, insert a magnesium strip, place a piece of filter paper 10 cm above the crucible, and ignite the magnesium strip to initiate the reaction.

Evaluation guide:
(i) Target concept: Self-sustaining exothermic redox reaction initiated by localized high-temperature ignition, resulting in phase change and radiative energy transfer to proximal objects.
Minimum mechanism: Ignition of Mg must precede and trigger crucible incandescence; incandescence must originate internally and propagate visibly; radiant heat from molten reaction zone must cause thermal degradation (charring) of filter paper at fixed vertical offset.
(ii)Storyline: Frame 1–2: Static setup: crucible with mixture, inserted Mg strip, filter paper suspended above. Frame 3–4: Mg tip ignites → bright white flash. Frame 5–7: Incandescence emerges from crucible interior, intensifies, and causes visible surface liquefaction. Frame 8–10: Filter paper edges darken and curl progressively while incandescence peaks; no external flame impinges on paper; charring results solely from radiant heat.

Manual:
Experimental Procedure
1. Place aluminum powder and iron oxide (1:3 mass ratio, Al:Fe₂O₃) into a refractory crucible.
2. Insert a magnesium strip vertically into the mixture.
3. Position a dry filter paper horizontally 10 cm above crucible rim.
4. Ignite the tip of the magnesium strip.
Observation of Experimental Phenomena
- Bright white light from burning magnesium.
- Immediate intense white-yellow incandescence inside crucible.
- Mixture becomes molten with surface shimmer and flow-like undulation.
- Filter paper above crucible chars (darkens and curls).
Summary of Experimental Principles
The thermite reaction (2Al + Fe₂O₃ → Al₂O₃ + 2Fe) is highly exothermic. Magnesium acts as a starter fuse due to its low ignition temperature. The heat released melts the products, producing molten iron and alumina slag.

Prompt Grounding rubric:
level_1: No crucible is shown; no aluminum powder or iron oxide is visible; no magnesium strip appears; no filter paper is positioned above the crucible; the ignition action never happens; none of the required setup elements appear together.
level_2: Only some of the required items appear (for example the crucible, or the magnesium strip, or the filter paper, but not the full set), and the procedure is out of order or incomplete: the crucible is empty or holds the wrong material, the filter paper is missing or not aligned above the crucible (e.g., placed inside it, below it, or off to the side), or the magnesium strip lies beside the mixture rather than inserted into it.
level_3: The crucible holds a visible powder mixture; a magnesium strip is inserted into that mixture; a piece of filter paper sits in the same shot, positioned above the crucible with a clear vertical gap between them; the ignition action (flame or spark reaching the magnesium strip) is shown; the crucible, aluminum powder, iron oxide, magnesium strip, and filter paper are all present.
level_4: Everything needed for the 3-point level is present, and in addition: the aluminum powder and iron oxide are visually distinguishable as two different granular materials within the crucible rather than one uniform mixture; the magnesium strip sits fully inserted with its tip buried in the mixture and its shaft protruding above; the filter paper lies flat and horizontal with nothing folding or blocking it; the ignition point is at the tip of the magnesium strip, not its side or base.
level_5: Everything needed for the 4-point level is present, and in addition: the crucible has the thick-walled, matte, ceramic look of refractory material rather than shiny metal; the aluminum powder looks silvery-gray and granular while the iron oxide looks rust-red/brown and powdery, occupying the same space in the crucible without visibly separating into layers; the magnesium strip is straight and unbroken from tip to end; the filter paper is white, rectangular, and unburnt before ignition, held at a height that makes its vertical offset above the crucible rim unambiguous.

Scientific and Causal Correctness rubric:
level_1: No thermal reaction is visible: no glow, no color change, no smoke, no motion in the crucible; the filter paper stays exactly as it started; nothing lights up and nothing is ejected from the mixture.
level_2: Some light or motion appears but doesn't match a thermite reaction: for example a blue gas-flame-like glow instead of white-hot incandescence, slow smoldering with no bright glow, or the mixture appearing to melt without ever glowing; the filter paper shows no darkening or curling; the crucible's contents look solid and unchanged after ignition; there's no visible link between the magnesium igniting and what happens next.
level_3: Igniting the magnesium strip produces a bright white flash, quickly followed by intense white-yellow incandescence from inside the crucible; the crucible's contents visibly turn molten (shimmering surface, flowing texture, loss of granular appearance); within that same continuous shot, the filter paper above shows charring: darkening, curling, or blackened patches.
level_4: Everything in the 3-point level holds, and in addition: the incandescence starts right where the magnesium strip was inserted, not somewhere else in the crucible; the mixture only turns molten after the incandescence begins, not before; the filter paper only starts charring once the crucible's glow is visible, showing a clear delay between ignition and charring; nothing implausible for this reaction appears (no explosion, no green or colored flame, no bubbling gas, no vapor cloud).
level_5: Everything in the 4-point level holds, and in addition: the molten core reads as noticeably brighter white-yellow than the darker crucible walls around it; the glow stays lit continuously without flickering out and relighting; the filter paper's charring visibly progresses (edges darken, then curl, then blacken) in step with the incandescence peaking; no sparks fly up toward the filter paper, no ash falls, and no second ignition point appears elsewhere.

Spatiotemporal Consistency rubric:
level_1: The crucible jumps to a different position between frames; the magnesium strip appears or disappears partway through; the filter paper's position or angle changes with no visible cause; the whole scene suddenly goes from lit to dark (or the reverse) in a single frame; the crucible looks cracked, melted out of shape, or otherwise structurally broken in a way this reaction wouldn't cause.
level_2: The crucible rotates or changes apparent size inconsistently between frames; the filter paper flickers in and out of view; the magnesium strip bends in a way that doesn't match how metal strips actually burn; a cast shadow suddenly points a different direction than it did a moment before with no light source moving; background objects shift sideways even though the camera isn't moving; the crucible glows before the magnesium is shown igniting, with no gradual build-up.
level_3: One small spatiotemporal flaw is present: for example, a hand or the crucible rim briefly blocks the filter paper and then the view clears again, the crucible shifts position slightly (less than about a tenth of the frame's height), or a single frame shows an odd bright reflection that doesn't repeat. Otherwise there is no breakage, no teleporting, and nothing happens out of causal order (e.g., charring before ignition).
level_4: Everything in the 3-point level holds, and in addition: the crucible top, the magnesium tip, and the center of the filter paper stay visible in every frame, never blocked from view; the direction and strength of the light stays the same for the whole sequence; the crucible stays in the same place in the frame with no unplanned zoom, pan, or tilt; the filter paper stays flat and horizontal; the magnesium strip stays visibly intact with no bending, breaking, or blurring at the tip.
level_5: Everything in the 4-point level holds, and in addition: the crucible rim, the filter paper's edges, and the magnesium tip show no visible drifting or shaking from one frame to the next; shadows cast by the glowing crucible fall consistently downward and away from it, matching a light source coming from the reaction itself; the sharpness of the magnesium strip and the background stay consistent with each other rather than one being crisp while the other blurs oddly; the crucible's base and rim keep believable proportions with no warping of its shape.