Year 9 Science · Unit 2 · Lesson 20

Materials Science, Unit Review

Foundation Worksheet

Name

Date

Class

Learning Goals

Recall the key concepts across the Unit 2 Materials unit.
Connect bonding type to material properties and applications.
Identify sustainability issues arising from material choices.

Warm Up

Fill the gap

Choose the correct word from the word bank to complete the paragraph below. Use each word once. Two words in the bank are distractors, they will not be used.

ionic covalent metallic polymer combustion finite biodegradable nucleus mixture

The type of bonding in a material determines its properties. Salt (NaCl) has bonding, where electrons transfer between atoms to form a rigid lattice with a high melting point. Water has bonding, where electrons are shared between atoms, giving it a lower melting point. Metals are held together by bonding, a "sea" of delocalised electrons, making them excellent conductors. When alkanes from crude oil undergo , they release energy along with CO₂ and water. Alkene monomers can be joined to form a long-chain such as polyethylene. Crude oil is a resource; once burned, it cannot be replaced. A material is described as if microorganisms can break it down into harmless natural substances over time.

Your Turn

Sort it!

Write each item from the pool into the correct category box below. Each item belongs in exactly one box.

NaCl lattice methane polyethylene microplastics electron sea fractional distillation thermoset life cycle assessment covalent sharing alkane formula CₙH₂ₙ₊₂ monomer finite resource

Bonding

Hydrocarbons

Polymers

Sustainability

Show What You Know

1. Explain why metals conduct electricity but ionic compounds only conduct electricity when dissolved in water or melted. Use the idea of bonding in your answer.

Recall 2 marks

2. Name one natural polymer and one synthetic polymer. For each, state where it comes from and give one everyday use.

Recall 2 marks

Wrap Up

Write three key ideas you will remember from Unit 2.