Science 3&43rd Edition

Energy

Teo-Gwan Wai Lan

for use from 2014–2

018

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Science (3rd Edition) promotes science as inquiry by encouraging pupils to learn interactively and explore the environment beyond the Textbook. Through inquiry, pupils acquire knowledge and understanding, skills and processes, and, positive ethics and attitudes. Science is made real and relevant, and life-long learners are nurtured.

The contents in the Textbook facilitate the learning journeys of pupils to uncover the ‘scientist’ in each of them. It also develops 21st Century Competencies in them.

Features include:

Enables pupils to see the link between the past and present and arouses their interest to explore further. This is achieved through stories of scientists and other information that introduce and spark discussion in each theme.

Encourages a purposeful pursuit of knowledge by listing key learning objectives which are posed as questions to promote inquiry

Excites pupils and extends their knowledge beyond the main lesson with intriguing nuggets of information

Makes Science real and meaningful with information about Science in everyday life, society and the environment

Lets pupils see that Science is everywhere by showing connections between chapters, themes and upper block content

Fosters interpersonal and communication skills as pupils apply concepts and skills learnt in a different context through questions and group activities

Inspires a spirit of scientifi c inquiry with stories of famous scientists

Instills pupils with a sense of national pride and identity through information and questions about Singapore

Develops independent learners with research skills as pupils use the Internet to learn more

Grows self-directed, interactive and effective learners who actively contribute through project work as they research, collaborate, communicate and present

Theme Opener

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Energy

1 Light and shadows 2 • Why do we need light? • What are sources of light? • How are we able to see the objects around us? • Why are we able to see through some objects but not others? • How are shadows formed?

2 Heat and temperature 10 • What is heat? • What is temperature? • What is the difference between heat and temperature? • Why do things become hot or cold? • What are the effects of heat gain and heat loss on matter? • What are the effects of expansion and contraction in our daily lives? • What are good and poor conductors of heat?

My pals, Joe, Sue, Zoe and Dr Atom, are here!

Dr Atom

Come and learn Science with us! We ask questions that help you understand

Science better.

Yes! We ask questions to help

you explore and talk about Science.

Don't worry. I will guide you through your learning journey. You will find that Science can

be fun and exciting!

Joe Sue

Zoe

Let's explore and discover the

wonders of Science together!

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Energy is everywhere around us. To enable things to change and move, energy is needed. Living things such as animals and plants need energy to live, grow and reproduce. Non-living things such as cars and buses need energy to move.

Energy comes in different forms such as light and heat. Light makes a place bright, while heat makes a place warm. Let us fi nd out more about light and heat.

The SARS (Severe Acute Respiratory

Syndrome) outbreak happened in

Singapore in 2003. To prevent the

spread of the disease, thermometers

were used to fi nd out if people had

fever. Scientists and engineers in

Singapore developed an infrared fever

screening system to detect fever quickly.

How were thermometers used to help fi ght SARS?

Energy

Thermometers are used to

measure how hot something

is. Daniel Gabriel Fahrenheit

(1686 – 1736) was the scientist

who invented the mercury

thermometer and a scale to

accurately measure how hot

something actually is.

Who invented the mercury thermometer?

In 1714

In 2003

What types of thermometers are available now and how do they work?

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The light bulb is an important part

of our lives. Thomas Edison

(1847 – 1931) worked on

thousands of materials before

he managed to fi nd one that

allowed the light bulb to light up.

He fi nally succeeded due to his

creativity and perseverance.

Who invented the light bulb?

As you learn about light and heat in this book, ask yourself:

Use this book to explore light and heat. Enjoy your journey …

• How are light and heat used in everyday life?

• Why are light and heat important?

In 1879

How has the invention of

the light bulb improved our lives?

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Help! The lights are out and I can't

see a thing!

We are having a blackout.

If only my eyes can see in the dark! Why can't they?

Thanks! I can see

again now!

Light and shadows1• Why do we need light?• What are sources of light?• How are we able to see the objects around us?• Why are we able to see through some objects but not others?• How are shadows formed?

We are having a blackout.

If only my eyes can see in the dark! Why can't they?

Thanks! I can see

again now!

We are having a blackout!

Thanks! I can see

again now!

Energy2

Have you ever had a similar experience? What allows you to see things in the dark?

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Light and shadows 3Light and shadows 3

Some living things glow because they produce light. Use the Internet to fi nd out more about living things which produce light. Explain how the light helps them to survive.

Are these sources of light?

Light and shadows

Why do we need light?Light is a form of energy. We need light in order for us to see. Without light, we cannot see anything. Can you imagine a day without light?

What are sources of light?Not all objects give off light. Objects that give off light are known as sources of light. Those that do not give off light are not sources of light.

The Sun is our main source of light during the day. It makes our surroundings bright and allows us to see.

At night, we need lights and lamps to help us see. What other sources of light do we use at night?

. We need light in order . We need light in order

3

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How are we able to see the objects around us?We can see sources of light because they give off light. However, there are many objects that do not give off light. How are we able to see them?

To be able to see an object, there must be light shining on it. The light is refl ected from the object and enters our eyes.

A book does not give off its own light. You can see the book because the light that falls onto the book is refl ected into your eyes.

The Moon is not a source of light. It looks bright at night because it refl ects light from the Sun.

Workbook activity 1.1

light sourceeye

book

Energy4

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Workbook activity 1.2

Why are we able to see through some objects but not others?Look at the three cups shown below.

Different types of materials allow different amounts of light to pass through them.

We can see through an object clearly if it allows most of the light to pass through it.

We cannot see through an object clearly if it allows only some light to pass through it.

We cannot see through an object at all if it does not allow any light to pass through it.

Which of the cups above allows the most light to pass through it? Which one allows the least light to pass through it?

Some buildings are designed to allow sunlight into them. This reduces the use of electricity and saves energy. Buildings designed to save energy are called green buildings. We should build more of such buildings to save energy.

Cup A Cup B Cup C

What are the other properties of materials that you have learnt in Chapter 5 of the Diversity Textbook?

Can you see the strawberry key chain

clearly in each cup?

Light and shadows 5

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