Domain: Natural Science — Geology & Geophysics
Target concept: Oxide Minerals Resistant to Acid Reactions: A Comparison of Hematite and Calcite

Video generation prompt: On the experimental table, place white calcite on the left and reddish-brown hematite on the right; add the same weak acid to the surfaces of both using a pipette.

Evaluation guide:
(i) Target concept: Differential acid reactivity between carbonate (calcite) and oxide (hematite) minerals.
Minimum mechanism: Weak acid must contact solid mineral surfaces; CO₂ gas evolution requires carbonate ion (CO₃²⁻) availability and protonation; Fe₂O₃ lacks reactive anions under weakly acidic conditions and thus exhibits no observable surface reaction.
(ii)Storyline: [Frame 0–2] Stable wide shot: experimental table centered, white calcite fully visible on left, reddish-brown hematite fully visible on right, both unmoving, same lighting. [Frame 3–5] Pipette enters frame from top, descends steadily toward both minerals, tip aligned above surfaces. [Frame 6–8] Acid droplet released and contacts calcite surface → immediate onset of discrete, localized bubbling; same droplet (or second identical droplet) contacts hematite surface → no bubbling, no surface disturbance. [Frame 9–10] Final still: both minerals unchanged in color/shape/position; effervescence ongoing only on calcite; pipette withdrawn or held static; full visibility maintained throughout from fixed frontal viewpoint.

Manual:
Experimental Procedure
1. Place white calcite on left side of experimental table and reddish-brown hematite on right side.
2. Using a pipette, apply weak acid simultaneously or sequentially to the surface of each mineral.
Observation of Experimental Phenomena
- Calcite produces visible effervescence (bubbling/gas evolution); hematite shows no effervescence.
- Both minerals retain their original colors: calcite remains white, hematite remains reddish-brown.
- No dissolution, color change, or surface erosion occurs in either mineral during observation.
Summary of Experimental Principles
- Calcite (CaCO₃) reacts with weak acids to produce CO₂ gas, causing effervescence.
- Hematite (Fe₂O₃) is an oxide mineral resistant to weak acid reactions and remains inert.

Prompt Grounding rubric:
level_1: The experimental table, the calcite, the hematite, and the acid application are not all shown together: e.g., one or both minerals are missing, the pipette never appears, or no liquid is ever dispensed onto either mineral.
level_2: The table is visible and at least one mineral (calcite or hematite) is present, but the other mineral is missing, or the pipette never actually dispenses acid onto a mineral, or the two minerals are not placed on a shared surface.
level_3: The table holds both the white calcite and the reddish-brown hematite; a pipette is visibly used to apply liquid to at least one of them; the two minerals appear to be on the same surface, but their left/right placement relative to each other is unclear, or the colors are not clearly matched to the correct mineral.
level_4: Everything at level 3 holds, and additionally: the calcite sits on the left and the hematite sits on the right; the pipette applies acid to both minerals, one after the other or at the same time; neither mineral is swapped in color or position; both remain clearly visible from a single fixed camera angle.
level_5: Everything at level 4 holds, and additionally: the calcite stays visibly white and the hematite stays visibly reddish-brown for the entire sequence; the pipette tip stays at a consistent height and angle while dispensing onto each mineral; both minerals stay in frame, unobstructed and in their original left/right positions, from the first frame to the last.

Scientific and Causal Correctness rubric:
level_1: No reaction is visible on either mineral, or both minerals react the same way (e.g., both bubble, or both stay inert when one should react), or the acid is never actually applied to the correct mineral.
level_2: The reaction appears on the wrong mineral (hematite bubbles, or calcite shows no bubbling), or either mineral changes color, or bubbling appears on hematite instead of only calcite.
level_3: Visible gas bubbles form where the acid contacts the calcite; the hematite shows no bubbling anywhere the acid touches it; both minerals keep their original colors (white calcite, reddish-brown hematite); neither mineral visibly dissolves or changes shape.
level_4: Everything at level 3 holds, and additionally: the bubbling stays confined to the calcite's wetted surface with no stray bubbles on the hematite; neither mineral shows fading, darkening, or a change in surface sheen; the hematite's surface looks dry and unreactive throughout; the calcite's bubbling is clearly visible for as long as acid remains on it.
level_5: Everything at level 4 holds, and additionally: bubbling on the calcite starts promptly and visibly as soon as the acid droplet lands, with no noticeable pause, and no bubbles appear before contact or linger long after the acid visibly stops being added; the hematite shows zero visual response of any kind: no sheen change, no bubbling, no visible difference in wetting compared to before contact; the calcite's reaction stays purely gas bubbles, with no liquid splashing or visible surface erosion.

Spatiotemporal Consistency rubric:
level_1: Either mineral or the pipette appears or disappears abruptly between frames; the acid droplet appears already on a mineral with no visible delivery; the lighting flashes or cuts sharply with no clear cause; the table surface distorts or vanishes momentarily.
level_2: One mineral shifts position with no visible cause; the pipette jumps to a new spot without a visible transit path; the acid appears on a surface with no visible drop or stream leading to it; a shadow on one mineral suddenly changes direction with no corresponding camera or light movement.
level_3: Both minerals stay in the same place relative to each other for the whole sequence; the pipette moves continuously as it approaches and releases the acid; the acid travels as a coherent droplet from the pipette tip to the mineral surface; the overall lighting on the table stays reasonably steady throughout.
level_4: Everything at level 3 holds, and additionally: both minerals stay fully visible and unobstructed for the entire sequence; the pipette tip never passes through or overlaps a mineral's surface; the acid droplet stays a single coherent blob rather than fragmenting or stretching unnaturally; the motion throughout looks smooth, without freezing or jump-cutting.
level_5: Everything at level 4 holds, and additionally: neither mineral nor the camera shows any small wobble or drift across the sequence; the acid does not reach the hematite well before or after it reaches the calcite in a way that breaks the sense of one continuous action; no lens distortion changes either mineral's apparent shape; every step of the acid's path and the minerals' reactions unfolds as one physically continuous motion.