Domain: Natural Science — Physics
Target concept: Different Flame Emission Spectra from Alkaline Earth Metal Salts (Calcium)

Video generation prompt: In the laboratory, a metal wire loop is dipped into calcium salt powder in a ceramic dish, and then the metal wire loop is inserted into the same Bunsen burner flame.

Evaluation guide:
(i) Target concept: Flame test emission from calcium ions requires thermal excitation in oxidizing flame environment to produce transient, location-specific brick-red/orange-red luminescence.
Minimum mechanism: Calcium salt must be thermally stable enough to reach vapor phase without decomposition; flame must provide sufficient temperature (>1200°C) to atomize and excite Ca atoms; emission must be spatially colocalized with loop-flame contact zone and temporally locked to contact duration.
(ii)Storyline: [Phase 1] Static setup: ceramic dish with white powder centered left, Bunsen burner with steady blue flame centered right; fixed frontal viewpoint. [Phase 2] Loop dips vertically into powder: visible adherence of granular solid. [Phase 3] Loop lifts and moves horizontally/rightward in continuous motion toward flame. [Phase 4] Loop enters flame base: immediate onset of localized brick-red/orange-red emission *only* at contact point. [Phase 5] Loop withdraws: emission ceases synchronously with exit; no afterglow. Visibility constraint: all phases occur in full frame with no occlusion; flame and loop remain in focus; powder granularity and wire metallic texture discernible throughout.

Manual:
Experimental Procedure
1. A clean metal wire loop is dipped into white calcium salt powder in a ceramic dish.
2. The powder-coated loop is immediately inserted into the non-luminous (blue) cone of a Bunsen burner flame.
Observation of Experimental Phenomena
A distinct brick-red or orange-red flame emission appears *only while* the calcium-coated loop is inside the flame; emission vanishes instantly upon loop removal.
Summary of Experimental Principles
Calcium ions, when heated in a flame, undergo electronic excitation and emit photons at characteristic wavelengths (~622 nm, ~554 nm) producing brick-red/orange-red color — a signature emission spectrum for alkaline earth metals.

Prompt Grounding rubric:
level_1: No ceramic dish, no white calcium salt powder, no metal wire loop, and no Bunsen burner flame are shown; none of the three staged actions (dipping the loop into the powder, carrying it to the burner, and inserting it into the flame) occurs.
level_2: At least one staged element (the wire loop, the ceramic dish, or the Bunsen burner flame) appears on screen, but the loop is never dipped into any powder and never inserted into the flame; no calcium powder is shown clinging to the loop at any point.
level_3: The wire loop is dipped into visible white/off-white powder sitting in the ceramic dish, then carried to the Bunsen burner and inserted into its flame, with the three actions occurring in that order and powder visibly clinging to the loop before it reaches the flame.
level_4: The dip-carry-insert sequence plays out just as described above, and in addition the ceramic dish sits in the same frame as the burner base under one fixed camera angle, the loop stays fully unobstructed during both the dip and the insertion, and only a single loop is used throughout, never two loops or a mid-scene swap.
level_5: Every part of that stays true, and further the loop reads as shiny gray/silver metal, the powder stays confined to the dish with none spilled on the bench or burner, the flame remains on-screen with no cut or frame drop while the loop is inserted, and the loop rises into the flame from below in one continuous, unhesitating motion rather than being jabbed in and pulled back repeatedly.

Scientific and Causal Correctness rubric:
level_1: No color change accompanies the loop's insertion into the flame: the flame stays plain blue/yellow throughout, and no brick-red or orange-red glow appears at any point in the video.
level_2: The flame does change color, but not to calcium's brick-red/orange-red (for example it turns green, violet, or an intense yellow instead), or the brick-red/orange-red tint appears before the loop ever reaches the flame, or lingers on well after the loop has been pulled back out.
level_3: A brick-red or orange-red glow appears in the flame specifically while the calcium-coated loop sits inside it, stays confined to where the loop meets the flame, and fades out within the same continuous shot once the loop is withdrawn.
level_4: That localized, correctly timed glow holds, and additionally it stays confined to the flame's inner cone/tip around the loop rather than spreading to engulf the whole flame, with no second color (such as a green tinge suggesting copper contamination) showing up alongside it.
level_5: All of that remains true, and the glow also ignites the instant the loop touches the flame and cuts off the instant the loop leaves it, with no delay on either end, no lingering glow on the loop itself once removed, and a brightness that looks proportionate to the flame rather than artificially oversaturated or washed out.

Spatiotemporal Consistency rubric:
level_1: The loop jumps directly from the dish to the flame with no visible travel path, the flame's silhouette flickers in and out between frames rather than burning continuously, the dish or burner relocates between shots, the scene swings from bright to dark (or the reverse) mid-action for no reason, or the loop shows a kink or bend that appears or vanishes without cause.
level_2: The loop's carry from dish to flame stutters or skips (visibly jumping ahead rather than moving continuously), the flame's shape distorts oddly (flattening, splitting, or blinking out and back), the dish or burner appears to rotate or tilt inconsistently between shots, or the shadow cast by the loop swings to an opposite direction from one moment to the next despite no camera or light change.
level_3: The dish stays put beside the burner, the loop travels along one continuous, plausible path from dish to flame, the flame's natural flicker never breaks its overall shape or position, and neither the loop, the dish, nor the burner vanishes and reappears or jumps position mid-scene.
level_4: That steady placement and continuous motion hold, and beyond it the loop's travel from dish to flame is smooth with no visible speed-up/slow-down glitch, the flame keeps a steady height and inner/outer cone shape throughout, the camera framing shows no sudden parallax jump suggesting a repositioned camera, and the loop's position relative to the flame never misaligns from one frame to the next.
level_5: Everything above continues to hold, and on top of it the foreground motion of the loop tracks consistently against a stable background (no floating or sliding relative to the dish/burner), the flame's flicker rate and size stay natural and even rather than pulsing on a rhythm or freezing mid-flicker, and the edges of the loop and flame stay visually crisp and steady rather than shimmering or strobing as the video plays.