Year 9 Science · Unit 2 · Lesson 9
Foundation Worksheet
Learning Goals
Fill the gap
Choose the correct word from the word bank to complete the paragraph. Not all words will be used.
In metallic bonding, metal atoms release their valence electrons to form a regular of positive metal . The released electrons are not attached to any single atom; instead they form a of electrons, a cloud of electrons that moves freely through the entire metal structure. When a is applied across a metal, the free electrons drift and carry electric charge, this explains why metals conduct electricity. Metals are also (can be hammered into sheets) and (can be drawn into wire) because the electron sea allows ion layers to slide past each other without breaking the bond. Polished metals have a shiny because free electrons reflect light.
Odd one out
Circle the item that does not belong in each group. Then write the odd item and your reason in the answer column.
| # | Group | Your answer (odd one + reason) |
|---|---|---|
| 1 | copper, good conductor silver, good conductor aluminium, good conductor salt water, good conductor via ions | |
| 2 | malleable ductile conducts electricity brittle when struck | |
| 3 | positive metal cations delocalised electrons electrostatic attraction electron transfer to non-metal |
1. Describe the sea-of-electrons model of metallic bonding. What are the two types of particles present in a metal lattice and how do they interact?
2. Copper can be hammered flat or drawn into a very fine wire without breaking. Explain why metals are malleable and ductile using the sea-of-electrons model.
Wrap Up
In one sentence, what was the main idea of this lesson?