with free observation log

Soil may look like one material, but it is actually a mixture of many different components. In this simple soil jar experiment, students mix soil with water and observe how the materials separate into visible layers. Free Soil Jar Observation Log included.

Learning Objectives

Students will:

• observe and describe a soil sample;
• predict what will happen when soil is mixed with water;
• conduct a simple investigation;
• identify sand, silt, clay, and organic matter;
• record the layers that form inside a soil jar;
• recognize patterns in the way different soil particles settle;
• use observations as evidence to explain why some materials sink while others float.

NGSS Alignment

This lesson most directly supports NGSS 2-PS1-1: Matter and Its Interactions, which asks students to plan and conduct an investigation that describes and classifies materials according to their observable properties. See the official NGSS 2-PS1-1 standard.

Three-Dimensional Learning

Science and Engineering Practice: Planning and Carrying Out Investigations

Students help plan and conduct a collaborative investigation. They make a prediction, follow an agreed-upon procedure, observe the results, and record evidence.

Disciplinary Core Idea: PS1.A – Structure and Properties of Matter

Students discover that soil contains different types of matter. These materials can be described and classified using observable properties such as particle size, texture, and position in the jar.

Crosscutting Concept: Patterns

Students identify a pattern in the settled soil. Larger mineral grains usually settle near the bottom, smaller particles form layers above them, and some lightweight organic materials may float.

Important Alignment Note

The activity is most strongly aligned when students do more than label a prepared diagram. Allow them to make predictions, discuss what should remain the same for each group, observe their own jar, compare results, and explain their conclusions using evidence.

For Grade 3, this investigation works well as a review of material properties and as an introduction to Earth materials and scientific observation.

Materials

For each group, provide:

• one clear plastic jar with a tightly fitting lid;
• approximately 1–2 cups of garden or schoolyard soil;
• water;
• a small scoop or spoon;
• a magnifying glass;
• a tray or plastic table covering;
• a permanent marker or label;
• pencils and crayons or colored pencils;
• one copy of the Soil Jar Observation Log for each student.

Clear plastic containers are safer than glass jars in an elementary classroom.

Teacher Preparation

Collect soil from a safe, untreated area. Avoid locations that may contain animal waste, pesticides, fertilizers, broken glass, or other contaminants.

Choose mineral-rich garden or schoolyard soil instead of commercial potting mix. Potting mix often contains a large amount of organic material and may not produce clearly defined sand, silt, and clay layers.

Break apart large clumps before the lesson, but leave a few small pieces of leaves, roots, or twigs so students can observe organic matter.

Prepare one soil jar at least 24 hours before the lesson. This provides a backup example if the student jars have not settled clearly by the second session.

Safety

Remind students:

• Do not taste or smell the soil closely.
• Keep hands away from the face during the investigation.
• Make sure the lid is completely closed before shaking the jar.
• Shake the jar only over a tray and away from other students.
• Wash hands thoroughly after handling soil.

The teacher should supervise all soil collection and jar shaking.

Session 1: Engage and Explore

1. Introduce the Phenomenon

Show students a dry soil sample.

Ask:

• What do you notice about this soil?
• Does all of it look and feel the same?
• What materials might be hiding inside it?
• Do you think soil is one material or a mixture of materials?

Allow students to examine the soil with magnifying glasses. Encourage them to describe its color, texture, particle sizes, and any pieces of organic matter they notice.

2. Ask the Investigation Question

Write the investigation question where everyone can see it:

What will happen when we mix soil and water and then leave the mixture undisturbed?

Students may share or write predictions such as:

• All the soil will stay mixed with the water.
• The soil will sink to the bottom.
• Some materials will sink, but other materials will float.
• The soil will separate into different layers.

At this stage, accept all reasonable predictions. Students will evaluate their ideas after observing the results.

3. Plan a Consistent Investigation

Ask students what each group should keep the same so that the results can be compared.

Possible responses include:

• the size of the jar;
• the amount of soil;
• the amount of water;
• the length of shaking time;
• the length of settling time.

If groups use soil from different locations, label each jar with the collection location.

4. Set Up the Soil Jars

Have students complete the following steps:

1. Fill the clear jar approximately halfway with soil.
2. Add water until it is close to the top, leaving a small air space so the contents can move.
3. Close the lid tightly.
4. Shake the jar vigorously for approximately 60 seconds.
5. Place the jar on a stable surface.
6. Label it with the group members’ names and the soil collection location.
7. Leave the jar undisturbed overnight.

Invite students to observe the jar immediately after shaking. The water will probably appear very cloudy because small soil particles are suspended throughout it.

If time permits, observe the jars again after 5–10 minutes. Students may already notice that larger grains are beginning to collect at the bottom.

Session 2: Explain, Elaborate, and Evaluate

5. Observe the Settled Jars

Without moving or shaking the jars, ask students to look carefully at the results.

Have them complete the Soil Jar Observation Log by:

• drawing the layers they can see;
• labeling sand, silt, clay, and floating organic matter;
• noting colors, textures, and differences in layer thickness;
• answering why some materials sank while other materials floated.

Remind students to record what they actually observe. A jar with uneven or unclear layers is still a valid scientific result.

6. Identify the Layers

A typical soil jar may show the following arrangement:

Position in the jar	Likely material	What students may observe
Water surface	Floating organic matter	Small leaves, roots, bark, or other lightweight pieces
Top of the settled sediment	Clay	Very fine particles forming a thin, smooth layer
Middle sediment layer	Silt	Small particles with a smoother appearance than sand
Bottom of the jar	Sand	Larger, more visible grains that settled first

There may also be a section of clear or cloudy water above the clay layer.

7. Discuss the Science

Explain that soil is a mixture rather than a single material. Shaking spreads the soil particles throughout the water. When the jar is left undisturbed, gravity pulls the particles downward.

The particles do not all settle at the same rate:

• Sand grains are relatively large and settle quickly.
• Silt particles are smaller and settle more slowly.
• Clay particles are extremely small and may remain suspended for a long time before forming the upper mineral layer.
• Some lightweight organic matter may float because it is less dense than the mineral particles or contains trapped air.

Some organic material may sink or remain mixed with the soil. Real soil samples do not always form four perfectly distinct layers.

8. Compare Results

Invite groups to compare their jars.

Ask:

• Which layer is the thickest?
• Which layer is the thinnest?
• Did all jars form the same pattern?
• Which soil sample contained the most sand?
• Which jar had the most floating organic matter?
• What evidence shows that soil is a mixture?
• Did the results support your original prediction?

Help students distinguish between an observation and an explanation.

Observation: The largest grains are at the bottom of the jar.
Explanation: The larger grains settled faster than the smaller particles.

9. Construct an Evidence-Based Explanation

Use this sentence frame for younger students:

I learned that soil is made of __________. My evidence is __________.

For more independent writers:

Soil is a mixture of different materials. I know this because __________.

A complete response might be:

Soil is a mixture of different materials. I know this because the soil separated into sand, silt, clay, and organic matter inside the jar.

Assessment

Use the following evidence to assess student understanding:

• participation in the prediction and planning discussion;
• safe and accurate completion of the investigation;
• a drawing that represents the student’s actual jar;
• appropriate use of the vocabulary words;
• correct identification of the main layers;
• an explanation supported by observations.

Exit Ticket

Ask students to answer:

What evidence from the soil jar shows that soil contains different materials?

Differentiation

Support for Younger Students and Multilingual Learners

• Review the picture-supported word bank before the experiment.
• Provide labeled picture cards for sand, silt, clay, and organic matter.
• Let students discuss their observations with a partner before writing.
• Use sentence frames.
• Allow students to point to or orally name the layers.

Challenge for Advanced Learners

• Measure the thickness of each sediment layer.
• Compare soil collected from two different locations.
• Create a bar graph showing the thickness of the sand, silt, and clay layers.
• Observe and record the jar at several time intervals.
• Research how different soil types affect plant growth or water drainage.

Optional Extension: Soil and Erosion

Place equal amounts of different soil samples in shallow trays. Slowly pour the same amount of water over each sample and compare how much soil moves.

Students can then investigate ways to reduce erosion, such as adding mulch, rocks, grass, or plant roots. This extension can help build toward 2-ESS2-1, in which students compare solutions that slow or prevent wind or water from changing the land.

Teacher Answer Guide

Expected labels from top to bottom:

1. Floating Organic Matter
2. Clay
3. Silt
4. Sand

Suggested Response to the Prediction Question

The larger and heavier mineral particles sink. Sand settles first, followed by silt and clay. Some lightweight organic matter floats because it is less dense or contains trapped air.

Accept developmentally appropriate responses such as:

The heavy parts sink, and the light parts float.

Teacher Tips and Troubleshooting

The water is still cloudy:
Clay particles can take longer than 24 hours to settle. Leave the jar undisturbed for another day.

The layers are difficult to see:
Try a different outdoor soil sample. Commercial potting mix may contain too much organic matter to form clear mineral layers.

Only one or two layers formed:
This may indicate that the soil sample contains a large proportion of one particle type. Compare it with another sample instead of treating the result as incorrect.

The groups have different results:
Use the differences as evidence that soils from different locations do not contain identical proportions of sand, silt, clay, and organic matter.

Conclusion

The soil jar experiment turns an ordinary scoop of soil into an observable science phenomenon. By making predictions, conducting an investigation, recording patterns, and explaining results with evidence, students learn both what soil contains and how scientists study materials.

Use the Soil Jar Observation Log to help students document each layer and communicate what they discovered.

Frequently Asked Questions About the Soil Jar Experiment

More Soil Education Resources for Teachers

https://www.nextgenscience.org/pe/2-ps1-1-matter-and-its-interactions?utm_source=chatgpt.com

https://www.nrcs.usda.gov/resources/education-and-teaching-materials/soil-education?utm_source=chatgpt.com

https://www.soils4teachers.org/?utm_source=chatgpt.com