🧪 Part 1: Physical vs Chemical Changes

1. Which of the following is a chemical change?

Ice melting into water

Baking a pavlova

Breaking a piece of glass

Dissolving sugar in tea

2. What are the signs that a chemical reaction has occurred? (Tick all that apply)

Change in colour

Gas is produced

Change in temperature

Change in shape only

Formation of a precipitate (solid)

3. Circle the correct answer: When iron rusts, this is a _______ change because _______.

Physical / the iron just changes colour

Chemical / a new substance (rust) is formed

Physical / the iron is still iron

4. In Rotorua's geothermal areas, underground chemical reactions produce gases that create geysers. What evidence shows this is a chemical reaction?

🔬 Part 2: Balloon Chemistry Experiment

5. During the baking soda and vinegar experiment, describe what you observed:

What did you see? _________________________________

What did you hear? _________________________________

What happened to the balloon? _________________________

6. Explain why the balloon inflated during the experiment:

7. How do you know that mixing baking soda and vinegar caused a chemical reaction? Give at least two pieces of evidence:

Evidence 1: ________________________________________

Evidence 2: ________________________________________

🌋 Part 3: Chemistry in Aotearoa New Zealand

8. Match each New Zealand example to the type of change by drawing lines:

Cooking hangi food underground

Freezing Lake Taupo in winter

Volcanic lava cooling into rock

Burning wood in a fireplace

Chemical Change

Physical Change

Chemical Change

9. Think of one chemical reaction you see in everyday life (not from the examples above). Describe it and explain how you know it's a chemical reaction:

10. Extension Challenge: Research one chemical reaction that occurs in New Zealand's unique environment (geothermal areas, marine life, native plants). Write a short paragraph about it: