Science · 1st Grade

Active learning ideas

Changing Materials: Mixing

First graders learn best through hands-on exploration, especially when they can see, touch, and compare materials before and after mixing. When students actively mix substances like salt and water or flour and water, they connect the idea that combining materials can create new properties or even new substances.

• Common Core State Standards
• 2-PS1-2

• 20–40 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Inquiry Circle
• 40 min · Small Groups

Inquiry Circle: Mix and Observe Lab

Small groups receive three mixing challenges: salt and water, flour and water, and baking soda and vinegar. For each mix, they record the properties of the starting materials, make the mix, and then record the properties of the result. They compare the three results and describe which mix produced something that seemed most different from either starting material.

Analyze what happens when two different materials are mixed together.

Facilitation Tip

During Collaborative Investigation: Mix and Observe Lab, move among groups to ask guiding questions like, 'What do you notice about how the salt disappears in the water?' rather than giving answers directly.

What to look for

Provide students with two small cups, one with sand and one with water. Ask them to draw what happens when they mix them in a third cup. Then, ask: 'Did a new substance form? How do you know?'

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

Activity 02

• Think-Pair-Share
• 20 min · Pairs

Think-Pair-Share: Can We Get It Back?

After observing a salt-and-water mix, ask students whether they think they can get the salt back. Students pair to discuss how, then watch the teacher demonstrate placing some salt water in a shallow dish to allow evaporation over several days. At the follow-up session, students observe the remaining crystals and describe what they see.

Differentiate between a mixture and a new substance formed by mixing.

Facilitation Tip

For Think-Pair-Share: Can We Get It Back?, provide sentence stems to support student discussion, such as 'We mixed ___ and ___ and got ____. We think we can get it back because ____.'

What to look for

Show students a prepared mixture, like salt dissolved in water, and the original salt and water. Ask: 'What did we mix? What do you observe now? Is this a mixture or a new substance? How can you tell?'

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

Activity 03

• Gallery Walk
• 25 min · Individual

Gallery Walk: Before and After Mixing

Post paired photo cards showing 'before mixing' and 'after mixing' images for eight combinations: baking soda and vinegar, paint colors mixed, sand and gravel, flour and eggs, coffee grounds and water, sugar and water, clay colors mixed, and wood shavings and glue. Students categorize each pair as 'still separable' or 'formed something new' and note their observable evidence.

Design an experiment to create a new material by mixing.

Facilitation Tip

In Gallery Walk: Before and After Mixing, place the 'before' and 'after' samples side by side so students can physically compare properties like texture, color, and state of matter.

What to look for

Present a scenario: 'Imagine you mix baking soda and vinegar. You see fizzing and bubbles. What does this tell you about whether a new substance formed? How is this different from mixing sand and water?'

• Understand
• Apply
• Analyze
• Create
• Relationship Skills
• Social Awareness

Activity 04

• Simulation Game
• 30 min · Pairs

Simulation Game: The Oobleck Challenge

Each pair mixes 2 parts cornstarch and 1 part water to make oobleck. They observe its properties: does it flow like a liquid? Does it hold its shape like a solid? They test it by hitting it sharply, pressing slowly, and rolling it in their hands. Students describe what is puzzling about this mixture and compare its properties to both the cornstarch and the water separately.

Analyze what happens when two different materials are mixed together.

Facilitation Tip

During Simulation: The Oobleck Challenge, remind students that Oobleck is a special mixture that acts like both a solid and a liquid, so they should describe its behavior carefully.

What to look for

Provide students with two small cups, one with sand and one with water. Ask them to draw what happens when they mix them in a third cup. Then, ask: 'Did a new substance form? How do you know?'

• Apply
• Analyze
• Evaluate
• Create
• Social Awareness
• Decision-Making

A few notes on teaching this unit

Start with simple, safe mixtures like salt and water so students experience reversible changes first. Avoid using terms like 'chemical reaction' too early, as first graders focus on observable changes. Research shows that young students benefit from repeated exposure to the same concept through different activities, so revisit mixing in multiple lessons to reinforce understanding.

Students will describe whether a new substance formed, identify which properties changed, and explain why some mixtures can be reversed while others cannot. They will use evidence from their observations to support their claims.

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Watch Out for These Misconceptions

• During Collaborative Investigation: Mix and Observe Lab, watch for students who assume that all mixtures create new, permanent substances.

  Use the salt-water evaporation station in this lab to demonstrate that the salt remains after the water evaporates, showing that the original materials can be recovered.

• During Collaborative Investigation: Mix and Observe Lab, watch for students who think the original materials disappear entirely when mixed.

  Have students mix red and blue food coloring with water to create purple, then ask them to describe where the red and blue colors 'went' to reinforce the idea that the materials are still present but combined differently.

• After Simulation: The Oobleck Challenge, watch for students who assume that because they cannot see a change, nothing happened.

  Ask students to describe the texture of Oobleck with their hands and explain why it feels solid when squeezed but liquid when poured, showing that some changes are not visible but can be felt or observed through behavior.

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Methods used in this brief

• Inquiry Circle
• Think-Pair-Share
• Gallery Walk
• Simulation Game