Oobleck Explorers: Is It a Solid or a Liquid?

Materials Needed

• 1 cup cornstarch
• About 1/2 cup water
• Large bowl or tray
• Spoon or measuring cup
• Food coloring, optional
• Small cup or container
• Paper towels or a washable table covering
• Paper and crayons
• Smock or old shirt
• Hand-washing supplies

Safety note: Oobleck is for playing and observing, not eating. Keep it away from eyes and mouths. Do not pour it down the drain; let it dry and throw it in the trash.

Learning Objectives

By the end of the lesson, the child will be able to:

• Name three common states of matter: solid, liquid, and gas.
• Describe what happens when oobleck is tapped, squeezed, or left alone.
• Use simple steps of the scientific method: ask, guess, test, observe, and tell.
• Explain that oobleck acts like a solid when pushed quickly and like a liquid when moved slowly.
• Share an observation using words, gestures, drawings, or sentences.

Success Criteria

I can:

• Say or point to solid, liquid, and gas.
• Make a guess before testing.
• Test oobleck in at least two ways.
• Tell or show what I noticed.
• Use the words push, slow, fast, solid, and liquid.

Lesson Overview

• Age: 4 years
• Time: 35–45 minutes
• Setting: Homeschool, classroom, or small-group learning

Introduction: Hook and Objectives

Hook: The Mysterious Goo

Show the child the cornstarch and water. Ask:

• “What do you think we can make with these?”
• “Do you think our goo will act like a rock, water, or something different?”
• “Can something be a little bit like a solid and a little bit like a liquid?”

Tell the child:

“Today we are scientists. We will make a goo called oobleck. We will ask a question, make a guess, test our idea, look closely, and tell what we learned.”

Connect to Everyday Life

Invite the child to find or name examples of matter:

• Solid: a toy, block, spoon, or rock
• Liquid: water, milk, or juice
• Gas: air or the bubbles in a balloon

Explain in simple language:

“Matter is the stuff all around us. A solid keeps its shape. A liquid flows and takes the shape of its container. A gas spreads out in the air.”

Body: Learn and Investigate

Part 1: I Do — Introduce the Scientific Method

Use five simple science words. Make a hand motion for each one.

1. Ask: “What will oobleck do?” Place a hand behind your ear.
2. Guess: “What do you think will happen?” Tap your head.
3. Test: “Let’s try it.” Pretend to stir.
4. Observe: “Let’s look and feel carefully.” Make pretend binoculars.
5. Tell: “Let’s tell what we learned.” Place a hand near your mouth.

Say:

“Scientists do not have to guess perfectly. Scientists learn by testing.”

Part 2: I Do — Demonstrate the States of Matter

Use simple objects or movements to model each state:

• Hold a block: “This is a solid. It keeps its shape.”
• Pour water into a cup: “This is a liquid. It flows.”
• Wave your hands through the air: “This is a gas. We cannot see air, but it is around us.”

Introduce oobleck:

“Oobleck is a special mixture. It can act like a liquid when we move it slowly. It can act like a solid when we push it quickly. It is called a non-Newtonian fluid. That is a big science name for a fluid that does not always act like regular water.”

Part 3: Meet Isaac Newton

Say:

“Isaac Newton was a scientist who studied motion and forces. A force is a push or a pull. Newton helped people learn more about how things move. Our oobleck will help us explore pushes and pulls, too.”

Use a toy car, ball, or block:

• Push it gently: “This is a small push.”
• Push it quickly: “This is a fast push.”
• Ask: “What happened when I pushed harder?”

Keep the explanation brief and playful: “Newton liked asking questions about pushes, pulls, and motion. Today we are Newton scientists!”

Part 4: We Do — Make the Oobleck

1. Place 1 cup of cornstarch in a bowl.
2. Add water a little at a time while stirring.
3. Optional: Add one or two drops of food coloring.
4. Keep stirring until the mixture feels thick but can still flow when moved slowly.

Use this child-friendly language:

“We are making a special goo. Add, stir, and watch. If it is too watery, add more cornstarch. If it is too dry, add a tiny bit more water.”

Quick check: Ask, “Is oobleck a hard solid like a block? Is it a runny liquid like water? What do you notice?” Accept words, gestures, and facial expressions as answers.

Part 5: We Do — Test Oobleck Slowly and Quickly

Before each test, ask the child to make a guess. Record the guess with a simple drawing, a check mark, or the child's words.

Test A: Slow Stir

1. Place a spoon in the oobleck.
2. Stir slowly.
3. Ask, “Does it flow around the spoon?”

Say: “When we move slowly, oobleck acts more like a liquid.”

Test B: Fast Stir or Tap

1. Stir quickly or tap the surface with one finger.
2. Ask, “Does it feel soft and runny, or hard and firm?”

Say: “When we push quickly, oobleck acts more like a solid.”

Test C: Squeeze and Release

1. Help the child pick up a small amount.
2. Squeeze it gently.
3. Open the hand and watch it drip or flow.

Ask: “What happened when you squeezed it? What happened when you stopped?”

Test D: Make an Oobleck Ball

1. Roll a small amount quickly between the hands.
2. Stop moving the hands.
3. Watch the ball soften and flow.

Say: “Fast movement helps it act like a solid. When we stop, it acts more like a liquid.”

Part 6: You Do — Choose an Investigation

Let the child choose one or more investigations:

• Finger scientist: Tap, poke, and slowly drag a finger through the oobleck.
• Tool scientist: Test a spoon, craft stick, or small cup.
• Motion scientist: Make a fast oobleck ball and see what happens when movement stops.
• Artist scientist: Draw what oobleck looks like when it is moving slowly and quickly.
• Word scientist: Describe oobleck using words such as sticky, thick, runny, hard, soft, fast, and slow.

Prompt the child to follow the science steps:

1. “What is your question?”
2. “What is your guess?”
3. “What will you test?”
4. “What did you see or feel?”
5. “What will you tell another scientist?”

Formative Assessment

Check understanding during the activity by asking:

• “Which state of matter keeps its shape?”
• “Which state of matter flows?”
• “What happened when you moved oobleck slowly?”
• “What happened when you pushed it quickly?”
• “What was your guess? Did your test surprise you?”

Look for the child to:

• Notice a difference between slow and fast movement.
• Use words, gestures, or drawings to describe observations.
• Understand that a guess comes before a test.

Summative Assessment: Little Scientist Demonstration

Invite the child to demonstrate and explain:

1. Show how oobleck acts like a liquid.
2. Show how oobleck acts like a solid.
3. Name or point to one regular solid and one regular liquid.
4. Complete the sentence: “When I move oobleck slowly, it ______. When I push it quickly, it ______.”

Accept responses such as:

• “It flows.”
• “It gets hard.”
• “It is like a liquid slowly.”
• “It is like a solid when I tap it.”

Differentiation and Adaptations

For a Child Who Needs More Support

• Use only the words solid, liquid, slow, and fast at first.
• Demonstrate each action before asking the child to try.
• Offer two choices: “Did it flow or stay firm?”
• Use picture cards or simple drawings for ask, guess, test, observe, and tell.
• Allow pointing, acting, or drawing instead of speaking.

For a Child Ready for More

• Test different amounts of water and compare the mixtures.
• Ask whether a gentle tap and a hard tap feel different.
• Compare oobleck with honey, water, or yogurt.
• Create a simple chart labeled “slow” and “fast.”
• Explain that “non-Newtonian fluid” means it changes how it flows when a force is used.

Different Learning Formats

• Hands-on: Touch, stir, tap, squeeze, and roll the oobleck.
• Visual: Draw observations or use simple state-of-matter cards.
• Auditory: Talk through the science steps and repeat key words.
• Movement-based: Move slowly like a liquid and quickly like a firm oobleck ball.
• Digital option: Record a short video of the child making a guess and showing the test.

Conclusion: Closure and Recap

Clean-Up as a Science Task

Ask the child to help scrape the oobleck into the trash. Wipe the work area and wash hands. Say:

“Scientists take care of their tools and clean their work spaces.”

Review the Big Ideas

Say:

“Today we learned that matter can be a solid, liquid, or gas. Oobleck is a special non-Newtonian fluid. It can flow like a liquid when we move it slowly, but it can feel like a solid when we push it quickly. We used the scientific method: ask, guess, test, observe, and tell. We also learned that Isaac Newton studied pushes, pulls, and motion.”

Child Recap

Invite the child to finish these sentences:

• “A solid is ______.”
• “A liquid can ______.”
• “Oobleck acts like a liquid when ______.”
• “Oobleck acts like a solid when ______.”
• “My favorite test was ______.”

Optional Follow-Up Activities

• Go on a household hunt for solids, liquids, and gases.
• Read a simple book about Isaac Newton, motion, or matter.
• Make a “scientist notebook” page with the question, guess, drawing, and result.
• Move like matter: stand still like a solid, slide like a liquid, and wave freely like a gas.
• Ask, “What other things change when we push them fast or slow?”