Science · Year 2

Active learning ideas

Dissolving Solids in Liquids

This topic works best when students touch, see, and taste the changes that happen when solids meet liquids. Active learning lets them feel the difference between a grainy residue and a smooth solution, which builds lasting memory of the concepts of solute, solvent, and mixture.

• ACARA Content Descriptions
• AC9S2U04

• 15–45 min
• Pairs → Whole Class
• 3 activities

Activity 01

• Inquiry Circle
• 45 min · Small Groups

Inquiry Circle: The Great Mix-Up

Groups are given clear jars of water and various solids (sugar, sand, glitter, flour). They predict what will happen, mix them, and then categorise the results as 'dissolved' or 'still there'.

Explain what happens to sugar when it dissolves in water.

Facilitation Tip

In The Great Mix-Up, hand each group a labeled tray so students move from station to station without losing focus or materials.

What to look for

Provide students with small cups of water, sugar, and sand. Ask them to record in their science notebooks what happens when they add sugar and stir, and what happens when they add sand and stir. Then, ask them to write one sentence explaining why one 'disappeared' and the other did not.

• Analyze
• Evaluate
• Create
• Self-Management
• Self-Awareness

Activity 02

• Stations Rotation
• 40 min · Small Groups

Stations Rotation: Separation Challenge

Provide stations with pre-made mixtures like sand and water, or paperclips and rice. Students must use tools (sieves, magnets, filter paper) to separate the materials, recording which tool worked best for each mixture.

Compare the dissolving rates of salt and sand in water.

Facilitation Tip

During Separation Challenge, circulate with a timer so groups rotate every six minutes, keeping the energy high and the task manageable.

What to look for

Present students with a list of common household items (e.g., flour, oil, coffee grounds, Jell-O powder). Ask: 'Which of these do you predict will dissolve in water? Which will not? Explain your predictions using the words 'soluble' and 'insoluble'.

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

Activity 03

• Think-Pair-Share
• 15 min · Pairs

Think-Pair-Share: Why did it change?

Show a video of a chef mixing ingredients for a cake. Students think about which ingredients they can still see and which have 'hidden' away, then discuss with a partner why we mix things in the first place.

Predict which common household solids will dissolve in water.

Facilitation Tip

For Why did it change?, give each pair exactly one minute to discuss before sharing with the class so quiet students have space to think first.

What to look for

During the experiment, ask individual students: 'What is the solute in your cup?' and 'What is the solvent?' Observe their responses to gauge understanding of these key terms.

• Understand
• Apply
• Analyze
• Self-Awareness
• Relationship Skills

A few notes on teaching this unit

Teachers find that starting with familiar solids like salt, sugar, and sand helps students trust their senses before introducing less obvious cases like flour or chalk dust. Avoid rushing to the term soluble too soon; let students describe what they see first. Research shows that weighing solutions and tasting (when safe) builds stronger conceptual anchors than diagrams alone, so plan those steps deliberately.

Students will correctly use the words soluble and insoluble, weigh and taste to confirm mass and presence, and explain why some solids seem to vanish while others do not. Their notebooks should show clear observations and one-sentence reasoning that matches the evidence they collected.

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Watch Out for These Misconceptions

• During The Great Mix-Up, watch for students who say the sugar or salt has disappeared because they cannot see it after stirring.

  Have students weigh the sugar and water together before and after mixing to show the total mass stays the same, then let them taste the water to confirm the sweetness is still present even if invisible.

• During Separation Challenge, watch for students who believe any liquid can mix perfectly with water.

  Use the oil-and-water setup at one station so students observe the layers forming and discuss why some liquids are immiscible and will always stay separate.

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Methods used in this brief

• Inquiry Circle
• Stations Rotation
• Think-Pair-Share