Year 8 Science · Unit 2 · Lesson 14
Foundation Worksheet
Learning Goals
Fill the gap
Choose the correct word from the word bank. Two words will not be used.
Metals are found on the side and in the middle of the periodic table. Non-metals are found on the side. Metalloids sit along a line between them. Metals are shiny, conduct electricity and are , so they can be hammered flat. Most solid non-metals are and crumble when hit. Metalloids such as silicon are useful as in computer chips.
True or false? Fix the false ones
Circle T or F. If a statement is false, correct it on the line.
1. Every solid element is a metal.
Correct it:
2. Copper is used for electrical wiring because it conducts electricity well and can be drawn into thin wires.
Correct it:
3. All non-metals are gases at room temperature.
Correct it:
4. If a solid is shiny, it must be a metal.
Correct it:
Scenario: tidying the prep room
Four solid samples in the prep room have lost their labels. Each is a single element. A technician tests each one for conductivity, taps it with a hammer (wearing safety glasses) and rubs it with fine sandpaper.
| Sample | Globe lights? | Hammer test | After sanding | Metal, non-metal or metalloid? |
|---|---|---|---|---|
| W | Yes, brightly | Flattens | Shiny silver | |
| X | No | Shatters | Dull yellow | |
| Y | No (a sensitive meter shows a tiny current) | Shatters | Shiny grey | |
| Z | Yes | Crumbles | Dark grey, slightly shiny |
Source: sample test results.
1. Which sample passed all three metal tests? Name the three tests it passed.
2. Complete the last column of Table 1. Then explain why sample Y is most likely a metalloid.
3. A student says sample Z must be a metal because the globe lit. Use the other results for Z to explain why the student is wrong, and suggest what Z could be.
4. A blacksmith can hammer iron into a horseshoe, but a lump of sulfur shatters when hit. Compare iron and sulfur using three properties, say where each sits on the periodic table, and explain the blacksmith’s observation.
Fill the gap
left; right; staircase; malleable; brittle; semiconductors. Not used (2): magnetic, bottom.
True or false
1. False: many non-metals are solid, such as sulfur, carbon and iodine. 2. True. 3. False: some non-metals are solids (carbon, sulfur, phosphorus) and bromine is a liquid. 4. False: iodine crystals are shiny but iodine is a non-metal; use several properties, not only shine.
Go Deeper
1. Sample W: it conducts (the globe lights), it is malleable (flattens) and it is shiny after sanding (lustre). [2 marks: 1 sample, 1 all three tests]
2. W metal; X non-metal; Y metalloid; Z non-metal. Y has mixed properties: it is shiny like a metal but brittle like a non-metal, and it conducts only a tiny amount (a semiconductor). [3 marks: 1 column correct, 2 for two mixed properties of Y]
3. No single test is enough. Z crumbles instead of flattening, so it is not malleable, which does not fit a metal. Z is probably graphite (a form of carbon), a non-metal that conducts electricity. [3 marks: 1 one test is not enough, 1 uses the hammer result, 1 graphite or carbon]
Show What You Know
4. Marking guide (points expected): 1 iron is a metal in the middle of the table, and sulfur is a non-metal on the right; 1 each for three property comparisons (iron conducts, sulfur does not; iron is malleable, sulfur is brittle; iron is shiny when polished, sulfur is dull yellow), up to 3; 1 iron is malleable so it bends into shape without breaking, while brittle sulfur shatters. [5 marks]
Common error to watch for: classifying by a single property, such as calling sample Z a metal because it conducts, or iodine a metal because it is shiny.