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.

• 1st Grade
• Science
• 4 activities
• 20 min–40 min

Learning Objectives

1. Compare the properties of original materials with the properties of a mixture.
2. Identify whether a new substance has formed after mixing two or more materials.
3. Design a simple experiment to test the effect of mixing specific materials.
4. Explain the difference between a mixture and a new substance formed by mixing.

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.

Prepare & details

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.

Setup: Groups at tables with access to source materials

Materials: Source material collection, Inquiry cycle worksheet, Question generation protocol, Findings presentation template

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

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.

Prepare & details

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 ____.'

Setup: Standard classroom seating; students turn to a neighbor

Materials: Discussion prompt (projected or printed), Optional: recording sheet for pairs

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

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.

Prepare & details

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.

Setup: Wall space or tables arranged around room perimeter

Materials: Large paper/poster boards, Markers, Sticky notes for feedback

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

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.

Prepare & details

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.

Setup: Flexible space for group stations

Materials: Role cards with goals/resources, Game currency or tokens, Round tracker

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

Teaching This Topic

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.

What to Expect

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.

Watch Out for These Misconceptions

Common Misconception

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

What to Teach Instead

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.

Common Misconception

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

What to Teach Instead

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.

Common Misconception

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

What to Teach Instead

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.

Assessment Ideas

Exit Ticket

After Collaborative Investigation: Mix and Observe Lab, give students two small cups, one with sand and one with water, and 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?' Collect drawings to assess their understanding of mixtures vs. new substances.

Quick Check

After Collaborative Investigation: Mix and Observe Lab, show students a prepared mixture of salt dissolved in water alongside 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?' Listen for responses that mention the salt being 'hidden' in the water but still present.

Discussion Prompt

During Think-Pair-Share: Can We Get It Back?, 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?' Use student responses to assess their ability to distinguish between chemical changes and physical mixtures.

Extensions & Scaffolding

• Challenge students to design their own mixture using two household materials, predict what will happen, and test their ideas during free exploration time.
• For students who struggle, provide pre-mixed samples with clear labels (e.g., 'salt and water mix') and ask them to describe what they see without focusing on whether a new substance formed yet.
• Deeper exploration: Introduce a mystery mixture (e.g., cornstarch and water) and ask students to investigate its properties, comparing it to Oobleck to notice similarities and differences in behavior.

Key Vocabulary

mixture	A combination of two or more substances that are physically blended but not chemically bonded. The original substances keep their own properties.
new substance	A material formed when substances are mixed and chemically change, resulting in new properties that the original substances did not have.
properties	The characteristics of a material, such as color, texture, hardness, or how it behaves when mixed with other things.
dissolve	To mix one substance into another so that it disappears and forms a solution, like sugar dissolving in water.