Year 8 Science · Unit 3 · Lesson 25

Weathering and Erosion

Challenge Worksheet

Name
Date
Class

Learning Goals

Warm Up

Because… chain

The Jenolan Caves formed through a long chain of chemical weathering events. Fill in the missing effects in the chain below.

Rainwater absorbs CO₂ from the atmosphere as it falls.
→
Carbonic acid (H₂CO₃) forms in the rainwater.
→
The acidic water seeps into cracks in the limestone bedrock.
→
Dissolved calcium carbonate is carried away in the water over millions of years.
→
Water drips into an air-filled cave chamber and CO₂ is released.
→

Overall outcome: what type of landscape does this process create over millions of years?

Go Deeper

Design challenge

A scientist wants to investigate whether warmer temperatures cause limestone to dissolve faster in carbonic acid. Design a valid controlled investigation to test this. Include all components of a good experimental design.

Design a mini-experiment

Complete the investigation design table below.

Aim (what you are testing)
Hypothesis (prediction using scientific reasoning)
Independent variable (what you will change)
Dependent variable (what you will measure)
Controlled variables (list at least 3 things kept the same)
Materials needed
Brief method (numbered steps, at least 4)
Predicted result (what you expect to see if your hypothesis is correct)
One limitation of this design (what could affect the reliability of results?)

Wrap Up

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

HSCScience · Year 8 Science · Unit 3 · Lesson 25 · Challenge Worksheet