Exercise Phase Change diagram showing molecular behavior in solid, liquid, and gas states with phase transition terms.

Let's solve this Phase Change diagram step by step.

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🔍 Step 1: Understand the States of Matter

We are given three descriptions of molecular behavior:

1. "Molecules are tightly packed in a regular array and move very little relative to each other"
→ This describes a Solid.

2. "Molecules are close together but move relative to each other"
→ This describes a Liquid.

3. "Molecules are far apart and fill the available place"
→ This describes a Gas.

So, we can label the three boxes accordingly:

- Left box (tight packing) → Solid
- Middle box (close but moving) → Liquid
- Right box (far apart) → Gas

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🔁 Step 2: Identify Phase Changes

Now, let’s determine the correct phase change names for the arrows between the states.

#### From Solid → Liquid:
- This is Melting (solid turns into liquid).

#### From Liquid → Solid:
- This is Freezing (liquid turns into solid).

#### From Liquid → Gas:
- This is Vaporisation (liquid turns into gas).

#### From Gas → Liquid:
- This is Condensation (gas turns into liquid).

#### From Solid → Gas:
- This is Sublimation (solid directly to gas).

#### From Gas → Solid:
- This is Deposition (gas directly to solid).

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✔ Final Answer: Fill in the Diagram

Here's how the completed diagram should look:

```
PHASE CHANGE
↑ ↓
←→ ←→
[Solid] [Liquid] [Gas]
↑ ↑ ↑
←→ ←→ ←→
Freezing Melting Vaporisation
↘ ↙
Condensation
↑
Deposition
↑
Sublimation
```

But in the image layout:

- Left box (solid) → Label: Solid
- Middle box (liquid) → Label: Liquid
- Right box (gas) → Label: Gas

Now the arrows:

#### Between Solid ↔ Liquid:
- Solid → Liquid: Melting
- Liquid → Solid: Freezing

#### Between Liquid ↔ Gas:
- Liquid → Gas: Vaporisation
- Gas → Liquid: Condensation

#### Between Solid ↔ Gas:
- Solid → Gas: Sublimation
- Gas → Solid: Deposition

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🧩 Drag-and-Drop Solution:

| Box/Arrow | Correct Label |
|----------|----------------|
| Left blue box (molecules tightly packed) | Solid |
| Middle blue box (molecules close but moving) | Liquid |
| Right blue box (molecules far apart) | Gas |
| Arrow from Solid → Liquid | Melting |
| Arrow from Liquid → Solid | Freezing |
| Arrow from Liquid → Gas | Vaporisation |
| Arrow from Gas → Liquid | Condensation |
| Arrow from Solid → Gas | Sublimation |
| Arrow from Gas → Solid | Deposition |

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✔ Summary of Labels to Drag and Drop:

- Solid → left bottom box
- Liquid → middle bottom box
- Gas → right bottom box
- Melting → arrow from Solid → Liquid
- Freezing → arrow from Liquid → Solid
- Vaporisation → arrow from Liquid → Gas
- Condensation → arrow from Gas → Liquid
- Sublimation → arrow from Solid → Gas
- Deposition → arrow from Gas → Solid

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✔ Final Answer Completed!
You now know how to correctly label all parts of the phase change diagram.