Year 9 Science · Unit 2 · Lesson 8
Foundation Worksheet
Learning Goals
Match each term to its meaning
Write the letter of the matching meaning in the middle column.
| Term | Letter | Meaning |
|---|---|---|
| Ionic bond | A. The force that pulls any positive charge and negative charge together. | |
| Ionic lattice | B. Shatters, instead of bending, when it is struck. | |
| Electrolyte | C. A regular, repeating 3D arrangement of positive and negative ions. | |
| Brittle | D. A substance that conducts electricity when it is melted or dissolved in water. | |
| Electrostatic attraction | E. The attraction between oppositely charged ions that holds an ionic compound together. |
1. Name the two types of particle in solid sodium chloride, and give the charge on each.
Sort it: is this typical of an ionic compound?
Write each property in the correct box.
Typical of ionic compounds
Not typical of ionic compounds
Cause and effect
Fill the two empty boxes. Each arrow means “which causes”.
Scenario: lining a pottery kiln
A pottery kiln heats clay to about 1300 °C. The inside of the kiln must be lined with a material that stays solid at that temperature. The kiln maker is choosing between five ionic compounds.
| Formula | Charges on the ions | Melting point (°C) |
|---|---|---|
| LiF | 1+ and 1− | 845 |
| CaO | 2+ and 2− | 2613 |
| KCl | 1+ and 1− | 770 |
| MgO | 2+ and 2− | 2852 |
| NaBr | 1+ and 1− | 747 |
Source: data book values.
2. Which of the five compounds could line the kiln? Use the data to explain your choice.
3. Compare the compounds made of 1+ and 1− ions with those made of 2+ and 2− ions. Describe the pattern and suggest a reason for it.
4. Potassium chloride (KCl) is sold as a salt substitute. Explain how potassium (2,8,8,1) and chlorine (2,8,7) atoms form this ionic compound, and why solid KCl has a high melting point (770 °C).