Year 8 Chemistry

Matter

100

What are the three main states of matter? 

Solid, liquid, gas 

200

Classify water, oxygen, and iron as elements, compounds, or mixtures.

• Water: Compound

• Oxygen: Element

• Iron: Element

300

• Describe how the particles behave for a solid, a liquid and a gas.  Hint: A solid has particles that are very close together and don't move much. 

• Solid: particles tightly packed, fixed shape
• Liquid: particles close but can move, takes shape of container
• Gas: particles far apart, move freely

400

• : Explain how the particle arrangement differs between a pure substance and a mixture.

• Pure substance: uniform particles (e.g., all water molecules)

• Mixture: different particles mixed (e.g., salt water)

500

Justify whether air should be classified as a homogeneous or heterogeneous mixture using particle theory

Air is a homogeneous mixture because its components (oxygen, nitrogen, etc.) are evenly distributed and not visibly separate.

Physical and chemical changes

100

Is melting ice a physical or chemical change?

Physical change.

200

• : Identify two signs that a chemical change has occurred.
• HINT: Think about the spray experiment in year 7 - what happened when you sprayed the mixtures/chemicals onto the flame?

• Color change

• Gas production (bubbles)

300

• Provide one example of a physical change, and one example of a chemical change

• Physical: melting ice, tearing paper etc

• Chemical: rusting iron, burning wood etc

400

• : A student mixes vinegar and baking soda. Describe the evidence that a chemical change has occurred and explain why.

• Evidence: fizzing, temperature change, new substance formed (CO₂ gas)

• Explanation: chemical reaction between acid (vinegar) and base (baking soda)

500

Is dissolving salt in water a physical or chemical change? Why?

Physical change. Dissolving salt doesn’t change its chemical structure; it can be reversed by evaporation.

Scientific discovery

100

Name one famous scientist and their discovery.

Isaac Newton – laws of motion and gravity.

Alexander Fleming – Discovered penicillin, the first widely used antibiotic. 

Marie Curie – Discovered radioactivity and the elements polonium and radium.

Dr. Cass Hunter – Indigenous Social-Ecological Researcher with lots of environmental discoveries 

200

How did the invention of the microscope change scientific understanding of cells?

Microscopes allowed scientists to see cells, leading to cell theory.

300

• : Describe how new technology can lead to changes in scientific theories.

New tools (e.g., telescopes, DNA sequencers) provide data that challenge or refine existing theories.

400

• How has climate change research has evolved due to new data and modelling techniques?

Climate models and satellite data have improved understanding of global warming and its causes.

500

How have social, ethical, or technological factors have influenced the development of atomic theory over time

Atomic theory evolved from Dalton’s solid spheres to quantum models due to experimental evidence (e.g., Rutherford’s gold foil experiment) and technological advances.