Year 8 Science · Unit 2 · Lesson 17
Foundation Worksheet
Learning Goals
Fill the gap
Choose the correct word from the word bank. Each word is used once at most. Two words will not be used.
How well a material lets electricity pass through it is its . The mass of a material for each unit of its volume is its . The temperature at which a solid turns into a liquid is its . A metal that can be hammered into thin sheets without breaking is . A gold ring still looks like gold after two thousand years in the ground because gold is .
Put the metals in order of conductivity
Write 1 beside the metal that lets electricity through most easily, down to 4 for the one that lets it through least easily.
| Rank (1–4) | Metal |
|---|---|
| Aluminium (Al) | |
| Copper (Cu) | |
| Iron (Fe) | |
| Silver (Ag) |
Read the data
| Metal | Density (g/cm³) | Mass of a 100 cm³ block (g) |
|---|---|---|
| Aluminium (Al) | 2.7 | 270 |
| Titanium (Ti) | 4.5 | 450 |
| Iron (Fe) | 7.9 | |
| Copper (Cu) | 9.0 | 900 |
| Lead (Pb) | 11.3 |
Source: published densities of the pure metals, each rounded to one decimal place.
1. Which metal in Table 1 has the lowest density? Which has the highest?
2. Fill in the two empty cells of Table 1 (mass = density × 100). Then calculate how many times heavier the lead block is than the aluminium block, to one decimal place.
Lead block ÷ aluminium block = times
Scenario: the model-plane club
A model-plane club is choosing a metal sheet for the wings of a large model plane. The three sheets on offer are aluminium, iron and lead, all the same size and thickness. The wings must be light and still hold their shape in flight. Lead is soft and bends easily.
3. Recommend one metal for the wings. Use density data from Table 1 and the properties the wings need, and explain what would go wrong with each of the two metals you did not choose.
Fill the gap
conductivity; density; melting point; malleable; unreactive. Not used (2): colour, reactive.
Put the metals in order of conductivity
Reading down the table as printed: 3, 2, 4, 1.
(Silver is the best conductor, then copper, then aluminium, with iron far behind.)
Read the data
1. Lowest: aluminium (2.7 g/cm³). Highest: lead (11.3 g/cm³). [2 marks]
2. Iron 790 g; lead 1130 g. 1130 ÷ 270 = 4.19, so about 4.2 times heavier. [3 marks: 1 each cell, 1 ratio]
Show What You Know
3. Marking guide (points expected): 1 the wings need low density (light) and enough strength to hold their shape; 1 recommend aluminium; 1 aluminium has the lowest density (2.7 g/cm³, a 100 cm³ block is 270 g) and is strong enough; 1 iron is strong but about three times as dense (7.9 g/cm³), so the wings would be too heavy; 1 lead is the densest (11.3 g/cm³, about 4 times aluminium) and soft, so the wings would be far too heavy and would bend. [5 marks]
Common error to watch for: choosing iron because it is “the strongest”. The job needs two properties at once, and the winner is the metal that is good enough on both.