Visual guide to understanding physical properties like density and elasticity.

The worksheet provided focuses on the Properties of Matter. It explains various physical properties of materials and provides examples to illustrate each concept. Below is a detailed explanation of each property, along with the solution for the density calculation at the bottom.

---

1. Hardness

- Definition: How difficult it is to scratch something.
- Examples:
- A diamond is very hard because you can't scratch it.
- Soap is easy to scratch, so it is not hard.

2. Brittleness

- Definition: How easily something shatters when dropped or struck.
- Examples:
- Glass is brittle because it will easily shatter if dropped.
- Wood is not very brittle because it will not shatter if dropped.

3. Elasticity

- Definition: How much something can bend and return to its original shape.
- Examples:
- Rubber is very elastic because it can stretch without breaking.
- A pencil is not elastic because it will break if you bend it.

4. Malleability

- Definition: How easily something can be pounded into thin sheets.
- Examples:
- Gold is very malleable because you can pound it into very thin sheets.
- Ice is not malleable because it will shatter instead of spread out.

5. Viscosity

- Definition: How slowly a liquid pours (a measure of its thickness).
- Examples:
- Syrup pours very slowly, so it is very viscous.
- Water pours quickly, so it is not viscous.

6. Tensile Strength

- Definition: How hard it is to break something by pulling it.
- Examples:
- Spider webs have high tensile strength because they can be pulled very hard before breaking.
- Tissue paper is easily pulled apart, so it has very little tensile strength.

7. Density

- Definition: How compact an object is. Density is a measure of how tightly packed the atoms of a substance are.
- Key Points:
- More tightly packed atoms make a denser substance.
- Density formula:
\[
D = \frac{m}{V}
\]
where:
- \( D \) = Density (in g/mL or g/cm³)
- \( m \) = Mass (in grams)
- \( V \) = Volume (in mL or cm³)

#### Examples in the Worksheet:
1. Ping-Pong Ball vs. Golf Ball:
- Both are approximately the same size (volume), but the golf ball is heavier, so it is denser.

2. Density Comparison:
- If two objects have the same size (volume), the one with more mass is denser.
- If two objects have the same mass, the smaller one (less volume) is denser.

#### Density Calculation Example:
The worksheet provides an example calculation:
- Given: A 20-gram object has a volume of 5 cm³.
- Formula:
\[
D = \frac{m}{V}
\]
- Substitute values:
\[
D = \frac{20 \, \text{g}}{5 \, \text{cm}^3}
\]
- Solve:
\[
D = 4 \, \text{g/cm}^3
\]

---

Final Answer for the Density Calculation:

\[
\boxed{4 \, \text{g/cm}^3}
\]

This worksheet effectively uses visuals and examples to explain the properties of matter, making it easier to understand concepts like hardness, brittleness, elasticity, malleability, viscosity, tensile strength, and density. The density calculation demonstrates how to apply the formula \( D = \frac{m}{V} \) to find the density of an object.