Worksheets - Lets teach! Primary - Free Printable

Problem: Understanding What Happens When Materials Are Cooled

The worksheet asks students to explore the effects of cooling on materials and complete tasks related to this concept. Below is a detailed solution for each part of the worksheet.

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1. Write what it means to cool a material?

Answer:
Cooling a material means reducing its temperature, which can cause changes in its state or properties. For example, cooling can make a liquid turn into a solid (freezing) or a gas turn into a liquid (condensation).

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2. Complete the sentence.

Sentence: Most materials ________ when cooled.
Answer: shrink

Explanation: When most materials are cooled, their particles move more slowly and come closer together, causing the material to contract or shrink.

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3. Colour the correct word.

#### (a) Cooling can change a liquid into a ________.
- solid
- gas

Answer: solid

Explanation: Cooling a liquid causes it to freeze, turning it into a solid.

#### (b) Cooling liquids to make solids is called ________.
- melting
- freezing

Answer: freezing

Explanation: The process of changing a liquid into a solid by cooling is called freezing.

#### (c) Cooling can change a gas into a ________.
- liquid
- solid

Answer: liquid

Explanation: Cooling a gas causes it to condense, turning it into a liquid.

#### (d) Cooling gases to make liquids is called ________.
- condensing
- freezing

Answer: condensing

Explanation: The process of changing a gas into a liquid by cooling is called condensation.

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4. Tick the true statements.

#### (a) Cooling can be undone.
- True
Explanation: Cooling can be reversed by heating the material back to its original temperature.

#### (b) Freezing can not be undone.
- False
Explanation: Freezing can be undone by heating the solid to its melting point, which turns it back into a liquid.

#### (c) Ice cubes can become water again by heating.
- True
Explanation: Heating ice cubes (solids) will melt them back into liquid water.

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5. Write or draw some materials you have seen change by cooling.

Answer:
Here are some examples of materials that change state when cooled:
1. Water → Ice: When water is cooled below 0°C, it freezes into ice.
2. Steam → Water: When steam (water vapor) is cooled, it condenses into liquid water.
3. Mercury → Solid Mercury: At very low temperatures, mercury (a liquid metal at room temperature) can freeze into a solid.
4. Ammonia Gas → Liquid Ammonia: When ammonia gas is cooled, it condenses into liquid ammonia.

You can also draw these changes:
- Draw a glass of water turning into ice cubes.
- Draw steam forming droplets of water as it cools.
- Draw a thermometer showing mercury contracting as it cools.

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Final Answer Summary:

1. Cooling a material means reducing its temperature, which can cause changes in its state or properties.
2. Most materials shrink when cooled.
3.
- (a) solid
- (b) freezing
- (c) liquid
- (d) condensing
4.
- (a) True
- (b) False
- (c) True
5. Examples include water turning into ice, steam turning into liquid water, and mercury freezing at low temperatures.

Boxed Final Answer:
\[
\boxed{
\text{1. Reducing its temperature; 2. shrink; 3. (a) solid, (b) freezing, (c) liquid, (d) condensing; 4. (a) True, (b) False, (c) True; 5. Water → Ice, Steam → Water, Mercury → Solid Mercury}
}
\]