Create a simple, clear, educational **90-second vertical chemistry video in 9:16 aspect ratio (1080×1920)** for a Class 10 Bengali chemistry lesson.
## OVERALL STYLE
* High-quality 3D cartoon educational animation.
* 9:16 vertical format.
* Clean, bright classroom/laboratory environment.
* Very simple visuals; avoid unnecessary objects.
* Use smooth camera movement and simple transitions.
* Bengali voice-over, clear and teacher-like.
* Show only essential equations, numbers and diagrams on the board.
* The same teacher must appear in every scene.
## TEACHER CHARACTER — MUST REMAIN IDENTICAL
Use exactly the same teacher in every scene:
A friendly Indian/Bengali male chemistry teacher, around 35 years old, short neat black hair, round spectacles, light blue full-sleeve shirt, dark navy trousers, brown shoes, friendly expression, average build.
**Character consistency is extremely important.**
Do not change his face, hairstyle, spectacles, skin tone, clothing, body proportions, age, height or visual style between scenes.
---
## SCENE 1 — INDUCTIVE EXAMPLE: SHARBAT
**Duration:** 0–12 seconds
### VIDEO PROMPT
Show the same teacher standing beside a simple classroom table. On the table is one glass of lemonade and two spoons of syrup. The teacher points toward them. Then smoothly show five identical glasses of lemonade with the required proportional amount of syrup. Keep the visual extremely simple and easy for Class 10 students to understand. The teacher explains that when the number of glasses increases, the required syrup also increases in a fixed ratio.
### VOICE-OVER
“ধরো, এক গ্লাস শরবত বানাতে দুই চামচ সিরাপ লাগে। তাহলে একই অনুপাতে পাঁচ গ্লাস শরবত বানাতে আরও বেশি সিরাপ লাগবে। অর্থাৎ, শরবত আর সিরাপের পরিমাণের মধ্যে একটি নির্দিষ্ট অনুপাত থাকে।”
### NEGATIVE PROMPT
No other people, no students, no extra characters, no crowded classroom, no complicated objects, no wrong quantities, no random text, no English text, no distorted teacher, no character redesign, no change of clothes, no change of face, no realistic human appearance, no messy background, no exaggerated gestures.
---
## SCENE 2 — CHEMICAL REACTION ALSO HAS A FIXED RATIO
**Duration:** 12–23 seconds
### VIDEO PROMPT
The same teacher now stands beside a clean whiteboard. Display the chemical equation clearly and accurately:
**3Fe + 4H₂O(g) → Fe₃O₄ + 4H₂**
Teacher points first to the coefficient 3 before Fe and then to the coefficient 4 before H₂. Highlight these coefficients gently. Explain visually that chemical reactions also follow fixed molar ratios.
### VOICE-OVER
“ঠিক একইভাবে, রাসায়নিক বিক্রিয়াতেও পদার্থগুলো নির্দিষ্ট অনুপাতে বিক্রিয়া করে। এখানে তিন মোল লোহা চার মোল জলীয় বাষ্পের সঙ্গে বিক্রিয়া করে চার মোল হাইড্রোজেন তৈরি করে।”
### NEGATIVE PROMPT
No incorrect chemical equation, no H₂O liquid symbol, no O₂ as a product, no Fe₂O₃, no FeO, no incorrect subscripts, no incorrect coefficients, no molecular structure replacing the equation, no extra chemicals, no explosions, no fire, no laboratory danger, no other characters, no teacher redesign, no text distortion.
---
## SCENE 3 — IRON AND STEAM REACTION
**Duration:** 23–35 seconds
### VIDEO PROMPT
Show the same teacher beside a very simple 3D educational laboratory demonstration. Show red-hot iron represented by glowing reddish iron pieces inside a simple reaction tube. Steam, clearly represented as water vapor H₂O(g), passes over the heated iron. Show the conceptual formation of Fe₃O₄ and H₂. A separate simple collection container represents hydrogen collection. Keep everything schematic and educational, not a realistic dangerous experiment.
Display the equation:
**3Fe + 4H₂O(g) → Fe₃O₄ + 4H₂**
### VOICE-OVER
“লোহিত-তপ্ত লোহার ওপর দিয়ে জলীয় বাষ্প চালনা করলে লোহা ও জলীয় বাষ্পের মধ্যে বিক্রিয়া ঘটে এবং তৈরি হয় ম্যাগনেটাইট বা Fe₃O₄ ও হাইড্রোজেন গ্যাস।”
### NEGATIVE PROMPT
No explosion, no large flame, no dangerous laboratory scene, no liquid water flowing over iron, no electrolysis, no oxygen gas product, no incorrect iron oxide, no incorrect equation, no smoke cloud, no fire accident, no extra people, no teacher redesign, no distorted apparatus, no unreadable equation.
---
## SCENE 4 — GIVEN HYDROGEN VOLUME
**Duration:** 35–45 seconds
### VIDEO PROMPT
Return to the same teacher and the same classroom whiteboard. Show a simple gas container labelled:
**H₂ = 11.2 L**
Then show:
**STP**
and below it:
**1 mol gas = 22.4 L at STP**
Teacher points to 11.2 L and then to 22.4 L. Use a simple visual comparison showing that 11.2 L is half of 22.4 L.
### VOICE-OVER
“এখন প্রশ্নে দেওয়া আছে, STP-তে হাইড্রোজেন গ্যাসের আয়তন 11.2 লিটার। আমরা জানি, STP-তে এক মোল গ্যাসের আয়তন 22.4 লিটার।”
### NEGATIVE PROMPT
No incorrect STP value, no 24 L, no 22.7 L, no wrong units, no incorrect gas volume, no pressure-temperature calculations, no extra formulas, no crowded board, no teacher redesign, no extra characters, no distorted numbers.
---
## SCENE 5 — VOLUME TO MOLE
**Duration:** 45–56 seconds
### VIDEO PROMPT
The same teacher writes a very simple calculation on the whiteboard:
**22.4 L H₂ → 1 mol**
**11.2 L H₂ → 0.5 mol**
Visually show 11.2 L as exactly half of 22.4 L. Teacher points to the relationship. Keep the board uncluttered.
### VOICE-OVER
“তাই, 11.2 লিটার হাইড্রোজেন হলো 22.4 লিটারের অর্ধেক। সুতরাং, 11.2 লিটার হাইড্রোজেন গ্যাসের পরিমাণ হলো 0.5 মোল।”
### NEGATIVE PROMPT
No arithmetic error, no 1 mol answer, no 2 mol answer, no wrong conversion, no wrong units, no unnecessary equations, no cluttered board, no calculator graphics, no teacher redesign, no extra characters.
---
## SCENE 6 — USE THE REACTION RATIO
**Duration:** 56–68 seconds
### VIDEO PROMPT
The same teacher stands beside the whiteboard. Show the reaction ratio clearly:
**4 mol H₂ : 3 mol Fe**
Then show:
**0.5 mol H₂ : ? mol Fe**
Use simple arrows connecting the known hydrogen amount to the unknown iron amount. Do not reveal the final mass yet.
### VOICE-OVER
“এবার রাসায়নিক সমীকরণের অনুপাত ব্যবহার করব। চার মোল হাইড্রোজেনের জন্য প্রয়োজন তিন মোল লোহা। তাই 0.5 মোল হাইড্রোজেনের জন্য লোহার মোলের পরিমাণ অনুপাত থেকেই নির্ণয় করা যাবে।”
### NEGATIVE PROMPT
No wrong ratio, no 3:4 reversal, no incorrect coefficient, no final mass shown, no unrelated formula, no extra chemicals, no clutter, no other characters, no teacher redesign, no distorted numbers.
---
## SCENE 7 — MOLE OF IRON TO MASS
**Duration:** 68–80 seconds
### VIDEO PROMPT
The same teacher points to the calculated amount of Fe in moles. Beside him, show a simple educational balance containing iron pieces. On the whiteboard write:
**Mass of Fe = Mole of Fe × Molar Mass of Fe**
Then show:
**Molar mass of Fe = 56 g mol⁻¹**
Keep the visual simple and focused on converting mole into mass.
### VOICE-OVER
“লোহার মোলের পরিমাণ জানা গেলে এবার তার ভর নির্ণয় করা যাবে। এজন্য মোলের সঙ্গে লোহার মোলার ভর, অর্থাৎ 56 গ্রাম প্রতি মোল, গুণ করতে হবে।”
### NEGATIVE PROMPT
No wrong molar mass, no 55.85 displayed as the main value, no incorrect unit, no weighing person, no complicated balance, no extra chemicals, no distorted formula, no teacher redesign, no other characters.
---
## SCENE 8 — COMPLETE SOLVING PATH
**Duration:** 80–90 seconds
### VIDEO PROMPT
Show the same teacher smiling beside a clean whiteboard. Display a simple left-to-right flowchart:
**H₂ volume**
↓
**Mole of H₂**
↓
**Reaction ratio**
↓
**Mole of Fe**
↓
**Mass of Fe**
Teacher points to each step sequentially. Keep the final scene clean and visually memorable. Do not add unnecessary text.
### VOICE-OVER
“অর্থাৎ, সমস্যাটি সমাধানের ধারাটি হলো— প্রথমে হাইড্রোজেনের আয়তন থেকে মোল, তারপর রাসায়নিক সমীকরণের অনুপাত থেকে লোহার মোল এবং শেষে মোল থেকে লোহার ভর। এভাবেই ধাপে ধাপে উত্তর পাওয়া যায়।”
### NEGATIVE PROMPT
No extra characters, no students, no incorrect flowchart, no extra formulas, no unrelated chemistry concepts, no crowded board, no dramatic effects, no teacher redesign, no change in face, hairstyle, spectacles or clothing, no text distortion, no spelling mistakes.
---
## FINAL GLOBAL NEGATIVE PROMPT
Do not introduce any character other than the same teacher. Never change the teacher's appearance between scenes. No character morphing, no face changes, no hairstyle changes, no clothing changes, no age changes, no body-proportion changes. No incorrect chemistry, no incorrect equations, no wrong coefficients, no wrong chemical formulas, no wrong units, no dangerous laboratory activity, no explosions, no fire accidents, no electrolysis, no oxygen as a product, no liquid water instead of steam, no cluttered backgrounds, no unnecessary props, no random text, no spelling errors, no distorted Bengali text, no unreadable equations, no camera shake, no excessive transitions, no photorealistic humans.
## TECHNICAL REQUIREMENTS
* Aspect ratio: **9:16**
* Resolution: **1080 × 1920**
* Duration: approximately **90 seconds**
* Style: **3D cartoon educational animation**
* Language: **Bengali**
* Voice: clear, calm Bengali male teacher voice
* Same teacher in all 8 scenes
* Simple classroom/laboratory setting
* Smooth transitions
* Accurate chemistry notation
* Educational, clean and visually uncluttered presentation
