Domain: Healthcare — Pharmacy
Target concept: The Complexation of Metal Ions with Tetracycline Drugs

Video generation prompt: Two identical transparent containers are placed side by side. The left container is filled with a solution of tetracycline antibiotic combined with magnesium ion solution, while the right container contains a simulated solution of the tetracycline antibiotic alone. Changes in the state are observed.

Evaluation guide:
(i) Target concept: Chelation-driven optical change (turbidity + color shift) due to Mg²⁺–tetracycline complex formation.
Minimum mechanism: Tetracycline must be present in both containers; Mg²⁺ must be present only in left; complexation must occur rapidly in aqueous solution at room temperature, yielding a colloidal suspension with altered light scattering and absorption.
(ii)Storyline: Frame opens on static frontal view of two identical empty transparent containers side-by-side → tetracycline solution is added to both (visually identical initial state) → magnesium ion solution is added only to left container → post-addition state stabilizes → sustained contrast emerges: left container develops uniform turbidity and intensified yellow-brown hue, right remains clear and pale; all transitions occur within fixed viewpoint, no camera motion, no object entry/exit, no lighting variation.

Manual:
Experimental Procedure
1. Place two identical transparent containers side-by-side in fixed frontal view.
2. Fill left container with tetracycline antibiotic solution + magnesium ion solution.
3. Fill right container with tetracycline antibiotic solution alone.
4. Observe and compare visual states simultaneously.
Observation of Experimental Phenomena
Left container shows reduced transparency (cloudiness/turbidity) and/or deeper yellow-brown color compared to right container, which remains clearer and lighter.
Summary of Experimental Principles
Tetracycline antibiotics form insoluble chelation complexes with divalent cations like Mg²⁺, causing visible turbidity and color intensification — a key drug interaction affecting bioavailability in clinical settings.

Prompt Grounding rubric:
level_1: Only one transparent container appears, or neither container is shown; the two containers are not next to each other; neither container shows any tetracycline-related solution; both containers look like they contain exactly the same liquid, with no way to tell them apart.
level_2: Two transparent containers sit next to each other, but at least one holds a liquid that clearly is not a tetracycline solution, or both containers are missing tetracycline; a magnesium-ion component seems intended for the left side but isn't actually shown being added; there is no way to tell from the visuals which container is meant to be the left one and which is the right.
level_3: Two transparent containers sit next to each other in a fixed shot; the left container holds tetracycline solution with magnesium ions added; the right container holds tetracycline solution alone; both contain a visible liquid filling their container; no other object (labels, pipettes, hands) dominates the frame or blocks the view of either container.
level_4: All elements of score 3 are present AND: the left container consistently occupies the left half of the frame and the right container the right half for the whole clip; no extra elements (text overlays, arrows, floating icons, or a hand) enter the frame while the containers are being observed.
level_5: All elements of score 4 are present AND: both containers' edges are sharp and fully in view, with no part cropped out of frame; both containers keep the same shape, size, and see-through quality for the whole clip; no reflection artifact or shift in camera angle disrupts the side-by-side view; the camera stays completely still and facing forward with no panning, tilting, or zooming.

Scientific and Causal Correctness rubric:
level_1: The two containers look the same in color and clarity by the end of the clip; or the container without magnesium (right) is the one that darkens or clouds while the left stays clear (the reverse of the expected outcome); or the left container instead becomes clearer or brighter than at the start.
level_2: A visible difference does appear between the two containers, but it does not match tetracycline–Mg²⁺ complex formation: for example, the left container becomes clearer or lighter, or a solid visibly settles out in a way unrelated to chelation, or the right container is the one that darkens or clouds; or the difference only appears before the magnesium ion solution has been added, or only after the observation period has ended.
level_3: The left container ends up visibly different from the right: it looks less clear (more cloudy or turbid) and/or has taken on a deeper yellow-brown tone compared to the right container, which stays clearer and lighter in color; this difference holds steady and is visible for the whole observation period.
level_4: All elements of score 3 are present AND: the difference is confined to the liquid itself, with no visible solid settling to the bottom or floating on top; the left container's liquid does not take on a blue or green cast; neither container shows bubbles, layering, or separation that would be inconsistent with a chelation reaction happening in solution.
level_5: All elements of score 4 are present AND: the cloudiness and color change in the left container look even throughout the whole liquid, without streaks, patches, or a gradient from top to bottom; the right container stays uniformly clear and unchanged; the visible contrast between the two containers does not flicker or waver from one moment to the next.

Spatiotemporal Consistency rubric:
level_1: A container's position on screen jumps between frames; one container disappears and reappears partway through the clip; the lighting suddenly flashes, strobes, or the scene goes momentarily dark; a container's shape visibly warps or bends; the background behind the containers changes abruptly.
level_2: One container flickers in and out of visibility briefly; a container's position wobbles slightly from frame to frame; a brief flare of light partly obscures one container; a bit of motion blur makes a container's edge look distorted; something in the background shifts inconsistently between frames.
level_3: Both containers stay visible, fully in frame, and in the same position for the whole clip; neither container disappears, warps, or breaks apart; the direction and brightness of the light in the scene stay the same from start to finish; the background stays still and unchanging; neither container is ever unexpectedly blocked from view or cut from the frame.
level_4: All elements of score 3 are present AND: any motion in the scene is smooth and physically reasonable, without stutters, freezes, or a time-lapse look; the edges of both containers stay sharp and aligned with each other throughout; neither container appears to shift relative to the other in a way that suggests a changing camera angle; there is no doubled or ghosted image of either container.
level_5: All elements of score 4 are present AND: neither container shows any visible shake, shimmer, or flicker along its edges; the liquid surface and meniscus in each container stay flat and unchanged in shape across the whole clip; which container appears in front and which parts of the background sit behind stay visually consistent, with no confusing overlap between them.