CAMBRIDGE
UNIVERSITY PRESS
Cambridge Lower Secondary
Science
LEARNER'S BOOK 9
Mary Jones, Diane Fe ll owes-Freeman & Michael Smyth
CAMBRIDGE
UNIVERSITY PRESS
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First published 2013
Second edition 2021
20 19 18 I 7 16 15 14 13 12 11 I 0 9 8
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Introduction
>Introduction
Welcome to Stage 9 of Cambridge International Lower Secondary Science.
We hope this book will show you how interesting and exciting science can be.
Science is everywhere. Everyone uses science every day. Can you think of
examples of science that you have seen or used today?
Have you ever wondered about any of these questions?
•
How do scientists plan experiments to find out if their ideas are correct?
•
Why do people all look different from each other, even though we all
belong to the same species?
•
Why do elements react to form compounds?
•
How can we increase the rate at which a reaction takes place?
•
Where are stars formed?
•
How can two sounds result in silence?
You will work like a scientist to find answers to these questions and more. It
is good to talk about science as you investigate and learn. You will share your
ideas with classmates to help them understand, and listen to them when
you need reassurance. You will reflect on what you did and how you
did it, and ask yourself: 'would I do things differently next time?'
You will practise new skills and techniques, check your
progress, and challenge yourself to find out more.
You will make connections between the different
sciences, and how they link to maths, English
and other subjects.
We hope you enjoy thinking and working like
a scientist.
Mary Jones, Diane Fellowes-Freeman,
Michael Smyth
3
>
Contents
)
- - - - -
>Contents
Page Unit
8
1 Photosynthesis and the
carbon cycle
8
15
24
34
1. 1 Photosynthesis
1.2 More about photosynthesis
1.3 The carbon cycle
1.4 Climate change
48
48
2 Properties of materials
53
60
71
84
84
98
106
112
119
130
-
2 . 1 Atomic structure and the
Periodic Table
2.2 Trends in groups within the
Periodic Table
2 .3 Why elements react to form
compo unds
2.4 Simple and giant structures
3 Forces and energy
3.1 Density
3.2 Heat and temperature
3.3 Conservation of energy
3.4 Moving from hot to cold
3.5 Ways of transferring thermal
energy
3.6 Cooling by evaporation
142
142
148
155
159
4 Maintaining life
168
168
174
5 Reactivity
179
187
194
4
4. 1 Plants and water
4.2 Transpiration
4.3 Excretion in humans
4.4 Keeping a fe tu s healthy
5. 1 Reactivity and displacement
reactions
5.2 Using the reactivity series and
displacement reactions
5.3 Salts
5.4 Other ways of making salts
5.5 Rearranging atoms
>
Science
strand
Thinking and Working
Scientifically strand
Science in Context
Biology:
Structure and
function
Carrying out scientific
enquiry
Discuss how scientific
know ledge develops
over time by shared
understand ing and
investigation .
Earth and
space: Cycles
on Earth
Scientific enqu iry:
purpose and p lanning
Chemistry :
Materials and
t hei r structure
Chemistry:
Properties of
materials
Chemistry:
Cha nges to
materia ls
Models and
representations
Discuss how scientific
knowledge develops
over time by shared
understanding and
investigation.
Physics:
Forces and
energy
Chem istry:
Properties of
materia ls
Carrying out scientific
enquiry
Scientific enquiry:
ana lysis, evaluation
and conclusions
Scientific enquiry:
purpose and planning
Discuss how scientific
understanding is used
and developed by
people working on
their own and working
together such as the
peer-review process.
Biology: Life
processes
Models and
representations
Carrying out scientific
enquiry
Scientific enquiry:
ana lysis, eva luation
and co nclusions
Evaluate topics using
scientific understanding .
Discuss how scientific
knowledge develops
over time by shared
understanding and
investigation.
Chemistry:
Changes to
materia ls
Mode ls and
representations
Scientific enquiry:
purpose and planning
Describe how science
is used in different
societies and industries,
and how it is used in
research .