Domain: Natural Science — Chemistry
Target concept: Catalyst Surface Area Effect: Crushed and intact catalysts exhibit different bubble behavior.

Video generation prompt: Equal amounts of manganese dioxide in the form of intact particles were placed into a blue beaker, and the crushed powder was placed into a red beaker; an equal volume of hydrogen peroxide was added to both.

Evaluation guide:
(i) Target concept: Catalytic reaction rate depends on available surface area of solid catalyst.
Minimum mechanism: Hydrogen peroxide decomposition is heterogeneous, occurring only at MnO2–liquid interface; higher surface area → more active sites → faster O2 gas evolution → more frequent/larger bubble formation.
(ii)Storyline: Frame 0–2: Static shot showing red beaker (crushed MnO2) and blue beaker (intact MnO2) side-by-side, both empty except for solids. Frame 3–5: Synchronized pouring of colorless liquid (H2O2) into both beakers. Liquid level rises uniformly. Frame 6–10: Immediate onset of vigorous, rising, coalescing bubbles in red beaker; delayed, isolated, non-coalescing bubbles in blue beaker, all observed from fixed frontal viewpoint with full beaker visibility and no occlusion.

Manual:
Experimental Procedure
1. Place intact manganese dioxide particles into a blue beaker.
2. Place crushed manganese dioxide powder into a red beaker.
3. Add equal volume of hydrogen peroxide to both beakers simultaneously.
Observation of Experimental Phenomena
Crushed MnO2 (red beaker) produces rapid, dense, continuous bubbling; intact MnO2 (blue beaker) produces slow, sparse, intermittent bubbling.
Summary of Experimental Principles
Catalyst surface area effect: Crushing increases exposed surface area, accelerating hydrogen peroxide decomposition and increasing bubble production rate.

Prompt Grounding rubric:
level_1: No beakers are visible; or no manganese dioxide appears in either container; or hydrogen peroxide is never added; or only one beaker is shown; or the beakers are not colored red and blue; or the crushed and intact forms look identical (e.g., both look like a uniform powder or both like uniform lumps).
level_2: Two beakers appear, colored red and blue, but manganese dioxide is missing from at least one of them; or hydrogen peroxide is added to only one beaker; or both beakers hold the same physical form of MnO2 (both crushed or both intact); or the colors are swapped relative to form (red holds intact chunks, blue holds crushed powder) with no visual cue distinguishing the swap as intentional.
level_3: The red beaker visibly contains crushed, granular/powdery manganese dioxide and the blue beaker visibly contains intact, cohesive chunks of manganese dioxide; hydrogen peroxide of an equal volume is added to both beakers; every object and action named in the posted_prompt is present.
level_4: All elements from score 3 are present AND the two beakers sit next to each other in the same frame with the camera held steady; the hydrogen peroxide is poured into both beakers at essentially the same time, starting and ending together; the crushed and intact forms stay visually distinguishable throughout: no blurring, occlusion, or reshaping erases the difference between them.
level_5: All elements from score 4 are present AND the two beakers are placed directly adjacent, with no gap wider than one beaker's width between them; the crushed powder never clumps into a shape resembling intact chunks, and the intact chunks never fragment or scatter into a shape resembling crushed powder; the liquid level rises by the same amount in both beakers right after pouring; nothing obscures either beaker's contents at any point in the video.

Scientific and Causal Correctness rubric:
level_1: No bubbling appears in either beaker; or bubbling appears only in the intact-MnO2 (blue) beaker; or the bubbling looks identical in intensity, duration, and appearance in both beakers; or bubbling starts before the hydrogen peroxide is added.
level_2: Bubbling occurs in both beakers, but the timing is reversed (the intact-MnO2 beaker bubbles first or longer than the crushed one); or bubbling occurs but shows no visible difference in density, rate, or duration between the two beakers; or bubbles form only on the surface with no rising motion; or bubbling appears in the wrong beaker relative to its labeled contents.
level_3: Bubbling appears in both beakers after the hydrogen peroxide is added, and it is visibly more vigorous (more bubbles per area, faster onset, and/or longer duration) in the red beaker (crushed MnO2) than in the blue beaker (intact MnO2); bubbling never begins before the liquid makes contact with the solid.
level_4: All elements from score 3 are present AND bubbling in the red beaker is continuous and vigorous, with bubbles visibly rising, merging, and breaking at the surface; bubbling in the blue beaker is sparse and intermittent, with isolated bubbles and long gaps between them; at no point do the two beakers show matching bubble count, size, or frequency at the same time.
level_5: All elements from score 4 are present AND bubbling in the red beaker starts almost immediately after the liquid contacts the solid, with no noticeable delay beyond the pour itself; bubbling in the blue beaker starts later and stays visibly sparser, covering less than about 25% of the liquid surface compared to over 75% coverage in the red beaker at peak activity; no bubble behavior (collapse, sudden merging, erratic motion) contradicts the expected surface-area-driven reaction-rate difference.

Spatiotemporal Consistency rubric:
level_1: A beaker's position or appearance jumps abruptly between frames rather than staying put; a sudden lighting change makes the scene briefly unreadable; a beaker's shape visibly warps or stretches; the hydrogen peroxide liquid disappears and reappears without a pour or spill; the crushed and intact MnO2 forms morph into each other partway through the video.
level_2: One beaker flickers or disappears for two or more consecutive frames; the liquid level jumps up rather than rising smoothly during the pour; the camera rotates or zooms abruptly; the direction of shadows changes in a way inconsistent with a fixed light source; a background object shifts position even though the camera view is meant to be static.
level_3: Both beakers stay fully visible and in place throughout; hydrogen peroxide pours in a smooth, continuous stream into each beaker; nothing blocks either beaker's contents during or after pouring; the light source's direction and brightness stay the same across frames; neither beaker's rim or base visibly deforms.
level_4: All elements from score 3 are present AND the pouring into each beaker starts and finishes within the same short window (visually simultaneous); neither beaker visibly slides or shifts position once placed; a liquid meniscus forms naturally in both beakers after pouring; there is no visible tearing, ghosting, or strobing between frames.
level_5: All elements from score 4 are present AND no motion blur hides the bubble formation in either beaker; the camera shows no parallax shift that would indicate hidden movement; the liquid surface stays flat and calm after the pour, with no sloshing or visible vibration; the crushed powder keeps its granular texture without smearing into a solid mass; the intact chunks keep their visible edges and shape without breaking apart on their own.