Year 9 Science · Unit 2 · Lesson 02
Foundation Worksheet
Learning Goals
True or false? Fix the false ones
Circle T or F. If a statement is false, correct it on the line.
Diamond has the highest hardness on the Mohs scale, rated 10.
Correct it:
A material with high electrical conductivity would make a good insulator for covering electrical wires.
Correct it:
A material’s melting point is a chemical property, because melting changes the substance into something new.
Correct it:
Metals are good conductors of heat because they contain electrons that are free to move.
Correct it:
1. A student says: “A bigger piece of steel is denser than a small piece of steel.” Is the student correct? Explain your answer using the definition of density.
2. A rectangular block of pine measures 10 cm × 5 cm × 2 cm and has a mass of 50 g. Calculate its density. Water has a density of 1.0 g/cm³: will the block float or sink?
Density g/cm³
Float or sink?
Scenario: a scratch test
A geology class tried to scratch three unknown minerals, A, B and C, with objects of known Mohs hardness. An object can only scratch a mineral that is softer than it.
| Mineral | Fingernail (2.5) | Copper coin (3) | Glass (5.5) | Steel file (6.5) |
|---|---|---|---|---|
| A | ✓ | ✓ | ✓ | ✓ |
| B | ✗ | ✗ | ✓ | ✓ |
| C | ✗ | ✗ | ✗ | ✗ |
Mohs values of the test objects are typical values.
3. Between which two Mohs values is the hardness of mineral B? Explain how Table 1 shows this.
4. Quartz has a Mohs hardness of 7. Which mineral could be quartz? Explain why the scratch test alone cannot prove that it is quartz.
5. Describe how you would measure the density of a small, irregular rock in the school laboratory. Name the equipment, give the steps in order, and show how you would calculate the density.