# Lesson 138: Solid, liquid, gas basics

🔬 SCIENCE (40 Lessons) • 🟡 C. Materials and Matter

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## Objective

I can tell the difference between a solid, a liquid, and a gas. I can give simple examples like ice, water, and air and say how each one behaves.

## Materials

- Small ice cube on a plate (or a picture of ice)
- Clear cup with water or juice
- Small empty balloon (blown up once and tied) or a picture of a balloon
- Pencil and notebook or scrap paper

## Mini-lesson — Solid, liquid, gas

Many things around us are made of matter. Matter can be a solid, a liquid, or a gas.

Solids

- Solids keep their shape.
- A block of ice, a toy, and a book are solids.
- You can hold a solid and it does not flow away.

Liquids

- Liquids can be poured.
- They do not keep their own shape. They take the shape of the cup or bottle they are in.
- Water, milk, and juice are liquids.

Gases

- Gases often look invisible to us.
- The air we breathe is a gas.
- Gases can spread out and fill space, like air inside a balloon.

One example: water

- Ice is solid water.
- Water in a cup is a liquid.
- Steam or water vapour is water as a gas in the air.

We can use simple questions to help: Does it keep its shape? Can it be poured? Does it feel like air? This helps us decide if it is a solid, a liquid, or a gas.

Picture strip: Ice, water, and air

Ice — solid

Water — liquid

Balloon — gas inside

## Guided Practice — Solid or liquid or gas?

You will look at ice, water, and air in a balloon. Use simple words to say if each one is a solid, a liquid, or a gas.

1. Look at the ice: Touch it gently if it is safe. Does it keep its shape when you pick it up? Say, "Ice is a solid."
2. Look at the water: Watch it in the cup. Can it be poured into another cup? Say, "Water is a liquid."
3. Look at the balloon: Gently press the balloon. You cannot see the air, but it is inside. Say, "Air is a gas."
4. Draw three pictures: On your paper draw ice, water in a cup, and a balloon. Under each picture write "solid", "liquid", or "gas".
5. Use the tracing pad: Choose words like solid, liquid, gas, ice, or water from the dropdown and trace them slowly. Say the word as you write.
6. Finish with a sentence: Write one sentence such as "Ice is a solid that keeps its shape" or "Water is a liquid that can be poured".

Tracing Pad
Lines
Trace
Pen

## Practice 1 — Sort solids, liquids, and gases

Sort everyday examples into solid, liquid, or gas.

1. Draw three boxes on your paper and label them: "Solids", "Liquids", and "Gases".
2. Think of things you know, such as: ball, book, chair, water, milk, juice, air in a balloon, steam from a kettle.
3. Write or draw each thing in the box you think it belongs in. For example, "ball" goes in "Solids", "water" goes in "Liquids".
4. Talk with an adult about any you are unsure of. Use the questions: "Does it keep its shape?" and "Can it be poured?" to help you decide.

## Practice 2 — What can water be?

Think about how water can be a solid, a liquid, or a gas.

- Draw three pictures in a row and label them "solid", "liquid", and "gas".
- Under solid, draw ice cubes on a plate.
- Under liquid, draw water in a cup.
- Under gas, draw steam coming from a kettle or small wavy lines in the air.
- Write one short sentence, such as: "Ice is solid water." and "Water in a cup is liquid."

## Practice 3 — Solid, liquid, gas story

Tell a short story that includes a solid, a liquid, and a gas.

1. Choose one solid (for example, ice lolly or ball), one liquid (for example, juice or water), and one gas (for example, air in a balloon).
2. Draw a simple picture that shows all three together.
3. Write (or say) one or two sentences, such as: "I drink liquid juice, hold a solid ball, and the balloon is full of gas."
4. Point to each thing in your picture and tell someone if it is a solid, a liquid, or a gas.

## Quick Check — Solid, liquid, gas basics

Answer each question about solids, liquids, and gases. Use the ideas of keeping shape, being poured, and filling space.

1) Which word names one of the three basic states of matter?

Colour. Liquid. Loud.
The three basic states we are learning are solid, liquid, and gas.

2) Which list shows all three states?

Red, blue, green. Hot, cold, warm. Solid, liquid, gas.
Solid, liquid, and gas are the three states we are studying.

3) Which sentence about a solid is true?

It keeps its own shape. It is always invisible. It can be poured like water.
Solids keep their own shape unless we cut or break them.

4) Which is a good example of a solid?

Juice in a cup. Toy block. Air in a room.
A toy block is a solid that keeps its shape.

5) Which sentence about a liquid is true?

It always stays in a cube shape. It cannot move or be poured. It can be poured and takes the shape of its container.
Liquids change shape to match the cup or bottle they are in.

6) Which is a good example of a liquid?

Water in a glass. Brick wall. Balloon full of air.
Water in a glass is a liquid that can be poured.

7) Which sentence about a gas is true?

It always looks like a solid block. It can spread out and fill space like a room or balloon. It cannot move at all.
Gases spread out to fill the space available to them.

8) Which is a good example of a gas?

Book on a shelf. Milk in a bowl. Air inside a balloon.
The air inside a balloon is a gas that fills the balloon.

9) Which sentence about ice, water, and steam is true?

They are all forms of water in different states. Only ice is made of water. Steam is not water at all.
Ice, liquid water, and steam are all water in different states.

10) Which question helps you decide if something is a solid?

"What colour is it?" "Does it keep its shape when I move it?" "What sound does it make?"
Solids keep their shape even when we move them.

11) Which question helps you decide if something is a liquid?

"Can I sit on it?" "Is it always invisible?" "Can it be poured and change shape in a cup?"
Liquids can be poured and change shape to fit their container.

12) Which question helps you think about a gas?

"Is there air here, even if I cannot see it?" "Can I cut it into slices?" "Does it stay in a neat cube?"
Air is a gas we often cannot see, but it is still there.

13) A child says, "Juice is a liquid." Why is this a good idea?

Because juice keeps a cube shape. Because juice can be poured and takes the shape of the cup. Because juice is invisible like air.
Liquids like juice can be poured and take the shape of their container.

14) Why do we learn about solids, liquids, and gases?

To understand what things are made of and how they behave. So we never touch anything again. So we only talk about colours.
Knowing the states of matter helps us understand the world around us.

15) Which sentence shows a good understanding of solid, liquid, gas?

"Air is a solid and ice is a gas." "Water is always a solid." "Ice is a solid, water is a liquid, and air is a gas."
This sentence matches each example to the correct state of matter.

## Assessment (parent/teacher)

Student can name solids, liquids, and gases in simple everyday language. Student can say that solids keep their shape and give at least one example. Student can say that liquids can be poured and take the shape of their container. Student can say that gases like air are around us and can fill a balloon or room. Student can answer simple questions about solids, liquids, and gases with a short explanation.

## Exit ticket (student)

😀 I can explain simple differences between solids, liquids, and gases. 🙂 I know some facts about solids, liquids, and gases but still need more practice. 😅 Solids, liquids, and gases still feel a bit tricky to explain.

#### Next time I will practise…

Sorting examples into solid, liquid, or gas Talking about how water can be ice, liquid, or steam Using the words solid, liquid, gas in my own sentences
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