Science · Grade 3 · Matter and Its Properties · Term 2

Properties of Solids

Students will identify and describe the observable properties of various solid objects, such as shape, texture, and hardness.

• Ontario Curriculum Expectations
• 2-PS1-1

About This Topic

States of matter is a foundational topic where students learn to categorize the world into solids, liquids, and gases. In Grade 3, the focus is on identifying the unique properties of each state: solids have a definite shape, liquids flow and take the shape of their container, and gases expand to fill any space. This topic is essential for understanding how materials behave and how we use them in daily life.

In the Ontario curriculum, this unit encourages students to use their senses to observe and describe matter. It also introduces the idea that matter is made of tiny particles, even if we can't see them. This topic particularly benefits from hands-on, student-centered approaches where learners can manipulate different substances and observe how they change or stay the same in different containers.

Key Questions

1. Differentiate between the properties of different solid objects.
2. Explain why a solid maintains its shape and volume.
3. Compare the characteristics of a rock to those of a wooden block.

Learning Objectives

• Identify and describe at least three observable properties of various solid objects, including shape, texture, and hardness.
• Compare and contrast the properties of two different solid objects, such as a rock and a wooden block, using specific descriptive language.
• Explain in writing why a solid object maintains its shape and volume when placed in different containers.
• Classify common solid objects based on one or more of their observable properties.

Before You Start

Introduction to Observation Skills

Why: Students need to have developed basic observational skills using their senses to identify and describe properties of objects.

Classifying Objects

Why: Prior experience in sorting and grouping objects based on simple characteristics helps students in classifying solids by their properties.

Key Vocabulary

Solid	A state of matter that has a definite shape and a definite volume. Solids keep their shape no matter what container they are in.
Property	A characteristic of an object that can be observed or measured, such as color, shape, texture, or hardness.
Texture	The way an object feels when you touch it, for example, smooth, rough, bumpy, or soft.
Hardness	A property that describes how well an object resists being scratched or dented. For example, a diamond is very hard, while chalk is soft.
Shape	The outline or form of an object. Solids have a specific shape that does not change easily.

Watch Out for These Misconceptions

Common Misconception

Gases aren't real matter because they are invisible.

What to Teach Instead

Many children think 'matter' must be something you can touch or see. Using a scale to weigh a deflated vs. inflated basketball helps them see that air has mass and takes up space, proving it is matter.

Common Misconception

Powders (like sand or flour) are liquids because they can be poured.

What to Teach Instead

This is a common error. A collaborative investigation where students look at sand through a magnifying glass reveals that each grain is a tiny solid with its own shape, unlike a liquid which has no fixed shape.

Active Learning Ideas

Stations Rotation: Matter Detectives

Students visit stations with 'mystery bags' containing a solid (a rock), a liquid (syrup), and a gas (a scented balloon). They must use their senses to identify the state of matter and list three properties that helped them decide.

40 min·Small Groups

Simulation Game: The Particle Dance

Students act as particles. For 'solid,' they stand close and vibrate; for 'liquid,' they hold hands and move around each other; for 'gas,' they run freely across the gym. This helps them visualize the internal structure of matter.

20 min·Whole Class

Think-Pair-Share: Is Air Matter?

Ask students to prove that air is matter even though we can't see it. Partners brainstorm ideas (like blowing up a balloon or feeling wind) and then share their 'proof' with the class.

15 min·Pairs

Real-World Connections

• Construction workers, like carpenters and masons, must understand the properties of solids such as wood, concrete, and brick to build safe and sturdy structures. They select materials based on hardness, texture, and shape for different building components.
• Toy designers and manufacturers carefully choose materials with specific properties like flexibility, hardness, and texture to create safe and engaging toys for children. For instance, soft, pliable plastics are used for baby toys, while harder, more durable plastics are used for action figures.

Assessment Ideas

Exit Ticket

Provide each student with a small bag containing two different solid objects (e.g., a smooth stone and a rough piece of wood). Ask them to write two sentences describing the properties of each object and one sentence comparing them.

Quick Check

Present students with images of various solid objects. Ask them to point to or name objects that are 'hard' or 'rough'. Follow up by asking them to explain why a specific object, like a block, keeps its shape.

Discussion Prompt

Place a collection of different solid objects on a table. Ask students: 'How are these objects similar, and how are they different?' Guide the discussion to focus on observable properties like shape, texture, and hardness, prompting them to use specific descriptive words.

Frequently Asked Questions

How do I explain 'particles' to Grade 3 students?

Tell them to imagine that everything in the world is made of tiny, invisible LEGO bricks. In a solid, the bricks are glued tight; in a liquid, they are in a big pile they can slide through; and in a gas, the bricks are flying around like tiny birds.

What are some common Ontario examples of the three states?

Ice (solid), the Great Lakes (liquid), and the steam from a maple syrup evaporator (gas) are perfect local examples that help students connect the curriculum to their own province.

How can active learning help students understand states of matter?

Active learning, like the 'Particle Dance' simulation, turns an invisible concept into a physical experience. When students move their bodies to mimic particles, they develop a 'muscle memory' of how solids, liquids, and gases differ, which is much more lasting than a definition.

Is 'Oobleck' a good way to teach states of matter?

Yes! Making Oobleck (cornstarch and water) is a fantastic active learning mission. It challenges students' definitions because it acts like a solid when squeezed and a liquid when released, sparking great classroom debates about how we classify matter.

From the Blog

Free Lesson Plan Templates: Customizable Frameworks for Modern K-12 Classrooms

Download free lesson plan templates for every grade level, plus guidance on differentiation, formative assessment, and using AI to plan faster.