Classify properties as physical or chemical in this educational worksheet.

Task: Classify the following properties as either physical or chemical.

#### Definitions:
- Physical Properties: Characteristics of a substance that can be observed or measured without changing its chemical composition. Examples include color, density, melting point, boiling point, etc.
- Chemical Properties: Characteristics of a substance that describe its ability to undergo chemical reactions and change into other substances. Examples include flammability, reactivity with water, rusting, etc.

#### Solution:

Let's classify each property:

1. Blue color
- Physical property: Color is an observable characteristic that does not involve a chemical change.

2. Density
- Physical property: Density is a measurable property that describes mass per unit volume, without altering the substance's chemical identity.

3. Flammability
- Chemical property: Flammability refers to the ability of a substance to burn, which involves a chemical reaction.

4. Dissolves in water
- Chemical property: Dissolving often involves a chemical interaction between the substance and water, even though it may sometimes be reversible.

5. Boils at 100 degrees
- Physical property: Boiling point is a temperature at which a substance changes from liquid to gas, which is a physical change.

6. Scratches glass
- Physical property: This describes the hardness of a substance, which is a physical characteristic.

7. Sour taste
- Chemical property: Taste is related to how a substance interacts chemically with taste receptors.

8. Rusting
- Chemical property: Rusting is a chemical reaction where iron reacts with oxygen and water to form iron oxide.

9. Exploding fireworks
- Chemical property: Fireworks explode due to chemical reactions involving combustion.

10. Melting point
- Physical property: Melting point is the temperature at which a substance changes from solid to liquid, which is a physical change.

11. Reacts with H₂O to form gas
- Chemical property: Reacting with water to form a gas involves a chemical reaction.

12. Reacts with something to form H₂O
- Chemical property: Any reaction that forms water involves a chemical change.

13. Hardness
- Physical property: Hardness is a measure of a substance's resistance to being scratched or deformed, which is a physical characteristic.

14. Boiling point
- Physical property: Boiling point is the temperature at which a substance changes from liquid to gas, which is a physical change.

15. Luster (shine)
- Physical property: Luster describes the way a substance reflects light, which is a physical characteristic.

16. Odor
- Chemical property: Odor is related to the molecular structure of a substance and how it interacts with olfactory receptors, indicating a chemical property.

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Final Classification:

| Property | Physical Property | Chemical Property |
|------------------------------|-------------------|--------------------|
| Blue color | ✓ | |
| Density | ✓ | |
| Flammability | | ✓ |
| Dissolves in water | | ✓ |
| Boils at 100 degrees | ✓ | |
| Scratches glass | ✓ | |
| Sour taste | | ✓ |
| Rusting | | ✓ |
| Exploding fireworks | | ✓ |
| Melting point | ✓ | |
| Reacts with H₂O to form gas | | ✓ |
| Reacts with something to form H₂O | | ✓ |
| Hardness | ✓ | |
| Boiling point | ✓ | |
| Luster (shine) | ✓ | |
| Odor | | ✓ |

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Explanation:

- Physical properties are those that can be observed or measured without altering the substance's chemical composition. Examples include color, density, melting/boiling points, luster, and hardness.
- Chemical properties involve the substance's ability to undergo chemical reactions, such as flammability, reactivity with water, rusting, and odor.

Final Answer:

\boxed{
\begin{array}{|c|c|c|}
\hline
\text{Property} & \text{Physical Property} & \text{Chemical Property} \\
\hline
\text{Blue color} & \checkmark & \\
\text{Density} & \checkmark & \\
\text{Flammability} & & \checkmark \\
\text{Dissolves in water} & & \checkmark \\
\text{Boils at 100 degrees} & \checkmark & \\
\text{Scratches glass} & \checkmark & \\
\text{Sour taste} & & \checkmark \\
\text{Rusting} & & \checkmark \\
\text{Exploding fireworks} & & \checkmark \\
\text{Melting point} & \checkmark & \\
\text{Reacts with H₂O to form gas} & & \checkmark \\
\text{Reacts with something to form H₂O} & & \checkmark \\
\text{Hardness} & \checkmark & \\
\text{Boiling point} & \checkmark & \\
\text{Luster (shine)} & \checkmark & \\
\text{Odor} & & \checkmark \\
\hline
\end{array}
}