Year 8 Science · Unit 2 · Lesson 19

How Discovery Changed the Uses of Substances

Foundation Worksheet

Name

Date

Class

Learning Goals

Explain how scientific discoveries can change the uses of substances over time.
Identify examples where growing knowledge made substances safer or more useful.
Recognise that some uses became unsafe once the true properties of a substance were understood.

Warm Up

Sort it!

Write each item from the pool below into the correct column. Think about whether scientific discovery enabled that use, or whether better scientific understanding revealed a use was unsafe.

Aluminium in aircraft Radium watch dials Silicon in computer chips Radioactive health tonics Teflon cookware X-ray shoe fitting MRI using helium Asbestos insulation LED lighting using gallium Lead plumbing

A new use enabled by scientific discovery

A use that became UNSAFE once properties were better understood

Your Turn

Fill the gap

Choose the correct word from the word bank to complete the passage below. Each word is used once. Two words will not be used.

extraction expensive discovery process properties mass-produced applications nucleus compound

Before 1886, aluminium was extremely because scientists had not found a practical method of from bauxite ore. Napoleon III even served important guests on aluminium plates, a symbol of luxury at the time. The Hall-Héroult , invented in 1886, was a key scientific that made cheap aluminium possible. Once scientists understood the physical and chemical of aluminium, its lightness, strength and resistance to corrosion, new were developed rapidly. Aluminium products could now be for everyday use in transport, construction and packaging.

Show What You Know

1. Before the Hall-Héroult process was invented, why was aluminium more valuable than gold, even though it is one of the most common metals in Earth's crust?

Recall 2 marks

2. Name two substances from today's lesson whose uses changed because of improved scientific understanding. For each one, briefly describe how the use changed.

Recall 2 marks

Wrap Up

In one sentence, what was the main idea of this lesson?