Matter Has Many Forms

Overview

Students investigate matter as solids, liquids, and gases. They connect each state to observable properties, especially whether it keeps its own shape or takes the shape of a container, building on their experience describing and sorting everyday objects.

Learning intentions

Students will be able to:

• Identify examples of solids, liquids, and gases.
• Describe observable properties of different materials.
• Explain that solids keep a definite shape.
• Explain that liquids and gases take the shape of their containers.

Success criteria

• I can sort examples as solid, liquid, or gas.
• I can describe a material using properties such as shape, color, texture, or size.
• I can explain what happens to the shape of a solid, liquid, or gas in a container.
• I can use evidence from an observation to support my answer.

Curriculum links

• Properties of Matter — identifying objects and materials as solid, liquid, or gas.
• Properties of Matter — recognizing that solids have a definite shape and liquids and gases take the shape of their container.
• Properties of Matter — observing and measuring properties such as size, shape, color, temperature, weight, texture, and whether objects sink or float.
• Changes in Matter — recognizing that materials can be altered to change some of their properties.

Lesson structure (30 minutes)

1. 0–4 min · Hook and notice. Teacher opens the hook slide showing an ice cube, water in a cup, and steam rising from a warm drink, then asks, “Which one has its own shape?” Students silently predict, share with a partner, and explain what they notice.

2. 4–9 min · Teach the three states. Teacher uses the states of matter slides to introduce solid, liquid, and gas with familiar examples such as a pencil, juice, and air; clarify that matter takes up space and can be described by observable properties. Students repeat the state names, give one example for each, and demonstrate the difference between “keeps its shape” and “takes the shape of a container” with hand motions.

3. 9–17 min · Shape investigation. Teacher places a solid block, a small amount of water, and an inflated balloon or sealed bag of air near clear containers; model safe observation and remind students not to taste or touch materials without permission. In groups of three, students observe what happens when the solid, liquid, and gas are placed in or compared with different containers, recording shape, color, texture, and other visible properties on the matter observation worksheet.

4. 17–22 min · Sort and justify. Teacher displays the sorting activity slides with pictures of objects and materials, including a rock, milk, a balloon, a book, rain, and air; invite groups to discuss any examples that could be confusing. Students sort the examples on their worksheet and complete the sentence, “I know this is a ___ because ___.”

5. 22–27 min · Partner explanation. Teacher uses the discussion prompt slides to present three scenarios: a book moved to a new table, juice poured into a bowl, and air inside a balloon; circulate and ask, “What evidence supports your idea?” Students explain to a partner whether the material keeps its shape or takes the container’s shape, then listen for and correct one another’s ideas.

6. 27–30 min · Plenary and exit check. Teacher displays the final review slide and asks students to show one, two, or three fingers for solid, liquid, or gas as examples are named. Students complete the final two questions on the matter observation worksheet: “Which state keeps a definite shape?” and “Why does water look different in different containers?” Collect worksheets for assessment.

Resources

• the matter states slide deck
• the matter observation worksheet
• Solid block, toy, or small book
• Clear cup, bowl, and narrow container
• Small amount of water
• Inflated balloon or sealed bag of air
• Trays for group materials
• Pencils and clipboards
• Paper towels for spills

Assessment

• Listen during partner talk and group work for accurate use of solid, liquid, and gas and for evidence-based explanations.
• Review worksheet observations, checking whether students identify states correctly and connect shape to the type of matter.
• Use the final questions as an exit check; reteach with concrete examples for students who confuse a liquid’s shape with its amount.

Differentiation

• Support students with picture examples, gestures, repeated sentence frames such as “A ___ is a ___ because ___,” and a small word bank: solid, liquid, gas, shape, container, property.
• Pair English language learners with supportive peers and allow students to draw observations before labeling them; explicitly model the meanings of “definite,” “takes the shape,” and “container.”
• For students needing additional support, provide only three clearly contrasting examples first and complete the first worksheet row together.
• Challenge early finishers to describe a material using three properties and explain how changing its container changes—or does not change—its shape.