Embed Size (px)
Citation preview
iii
iii
c
Synergy for Success in Science Series is based on the science curriculum framework in Singapore, and meets the standards and competencies prescribed in the K to 12 science curriculum by the Department of Education. This framework aims to enable students acquire in-depth knowledge, understanding, and skills for mastery and application of science concepts that are relevant to daily life, society, and the environment. This book aims to develop students into lifelong learners with deep appreciation of scientific knowledge and processes, and equipped with scientific values and attitudes.
This book uses concrete examples and matches them with colorful visuals and language that is suited to the level of the students to whom this book is intended. This makes learning experience relevant, accessible, and meaningful to students regardless of their background and language skills.
This book makes science learning easier with the help of the following features:
Key Concept Important key words and concepts are defined, compared, and differentiated. This facilitates easy understanding of science concepts.
Know More This concept-related information enriches students knowledge and reinforces their understanding of science concepts, hence appreciate their applications.
Let’s Review These open-ended questions reinforce students understanding and mastery of science concepts in each lesson.
Let’s Do This These are simple classroom exercises that enable students to explore and apply science concepts in real-life experiences.
Chapter Summary This serves as a review guide for students.
Key Ideas summarizes important concepts at the end of each chapter.
Concept Map is a visual summary of the concepts presented in the chapter.
Chapter Test These multiple choice and structured questions enable students evaluate their knowledge, understanding, skills, and mastery of the concepts on their own.
Enrichment This contains suggested activities that students can do in relation to the topic in each chapter.
Making Connections This present practical application/s of the science concept discussed in the chapter.
PREFACE
iv
Table of Contents
unit 1 Earth and SpaceThe Internal Structure of Earth Layers of Earth 3 Theories of Diastrophism 9Chapter Summary 11Chapter Test 13Making Connections 16
Plate Tectonics Continental Drift Theory 18 The Theory of Plate Tectonics 21Chapter Summary 25Chapter Test 27Making Connections 29
1.1
Chapter 1
1.2
Chapter 2
2.1
2.2
Preface iii
unit 2 Force, Motion, and EnergyElectromagnetic Spectrum Electromagnetic Waves 33 Electromagnetic Spectrum 37Chapter Summary 44Chapter Test 46Making Connections 48
Light Mirrors 50 Lenses 63 Optical Instruments 74Chapter Summary 78Chapter Test 80Making Connections 83
3.1
Chapter 3
3.2
Chapter 4
4.1
4.2
4.3
v
Electricity and Magnetism
Electromagnetic Induction 86
Applications of Electromagnetic Induction 94
Chapter Summary 100
Chapter Test 102
Making Connections 105
5.1
Chapter 5
5.2
unit 3 Living Things and their EnvironmentCoordinated Functions of the Endocrine, Reproductive, and Nervous Systems
The Endocrine System 109
The Reproductive System 116
The Nervous System 130
Chapter Summary 141
Chapter Test 143
Making Connections 145
Heredity: Inheritance and Variation
Nucleic Acids: DNA and RNA 148
Central Dogma of Molecular Biology 155
Mutations 166
Chapter Summary 175
Chapter Test 177
Making Connections 179
Evolution
The Theory of Evolution 182
Evidence of Evolution 192
Chapter Summary 200
Chapter Test 202
Making Connections 205
Chapter 6
6.1
6.2
6.3
Chapter 7
7.1
7.2
7.3
Chapter 8
8.1
8.2
vi
Ecology Biodiversity and Ecosystem Stability 208 Population Ecology 217Chapter Summary 224Chapter Test 226Making Connections 229
9.1
Chapter 9
9.2
unit 4 The Science of MatterGas Laws Basic Properties of Gases 233 Gas Laws 237Chapter Summary 256Chapter Test 259Making Connections 262
Biomolecules Biomolecules 264 Carbohydrates 267 Lipids 272 Proteins 278Chapter Summary 285Chapter Test 287Making Connections 290
Chemical Reactions Chemical Equations 292 Patterns of Chemical Reactivity 298Chapter Summary 305Chapter Test 307Making Connections 309
Glossary 311Index 321
10.1
Chapter 10
10.2
Chapter 11
11.1
11.2
11.3
11.4
Chapter 12
12.1
12.2
Earth and SpaceUnit 1
Earthquakes occur when the stress under the plates is suddenly released. Last 2013, a 7.2–magnitude earthquake hit the province of Bohol in the
Philippines. The earthquake killed many people and destroyed houses, establishments, and even Loboc church, one of the old churches in the Philippines.
In this unit, the internal structure of Earth and their functions are discussed. The theories and the factors that explain the plate movements are also included in this unit.
2 Earth and Space
Chapter 1
The Internal Structure of Earth
Geologists describe Earth as an astronomical body composed of layers of rocks and minerals. Each layer has its own function that helps maintain the condition of Earth. The outer core, for example, helps in maintaining Earth’s magnetic field.
In this chapter, the layers of Earth and how they interact with one another are discussed.
LEARNING GOALS
•DescribetheinternalstructureofEarth.•DeterminethefunctionsofeachlayerofEarth.•Describeandanalyzethedifferenttheoriesofdiastrophism.
The Internal Structure of Earth 3
Know More!
Oceanfloorsarealsoknownassima.Thewordsimaisfromtheelementssilicateandmagnesium.Thesetwoarethemaincomponentsthatmakeuptheoceanfloors.
1.1 Layers of EarthEarth is divided into three layers namely, the crust, the mantle and the core. Each layer has its own composition, properties and characteristics.
Figure 1.1 Earthhasthreemajorlayers.Eachlayerisdividedintosublayers.
ocean
mantle
crust
core
Crust
The crustistheoutermostandthethinnestlayerofEarth. It ismadeupof igneous,sedimentary,andmetamorphicrocks.
The crust is broken up into plates. Plates are composed of great variety rocks that are made up of silicon, aluminum, minerals, and ores.
The crust has two types, namely, continental crust and oceanic crust.
Figure 1.2 ThethicknessofEarth'scrustisapproximately18miles
oceaniccrust
continentalcrust
uppermantle
4 Earth and Space
Continental crust
The continental crust covers almost 40 percent of Earth and makes up the continents. It is made up of sials, which are rocks made of granite rich in aluminum silicate. It has an approximate density of 2.6
gcm3
.
Oceanic crust
The oceanic crust is found beneath the ocean floor. It is formed from the lava that seeped up from mid-ocean ridges. These undersea mountain ranges have openings where the magma comes out. Cooled by the seawater, the lava covers the sea floor, thus, forming a new oceanic crust.
Lavaisthemagmathatseepedupfromvolcanoesormid‑oceanridges.Magma is a mixture of hot liquid base, mineralcrystals, semi‑molten rocks, anddissolvedgases.ItisfoundbeneaththesurfaceofEarth.
The oceanic crust is thinner and denser than the continental crust. It has an approximate density of density
gcm3
=
3 . On the
average, it is about 4 miles thick. It is made up of dark-colored igneous rocks known as basalt rocks.
Abasalt rockisanigneousrockthatismadeupofsilicon,oxygen,andmagnesium.
Mantle
ThemantleisthethickestlayerofEarth.Itconsistsofhot,densesilicaterockshellwhichismadeupofsilicon,oxygen,andotherelements.
The mantle lies between the core and the crust. It is divided into the upper and lower mantle. The upper mantle includes the lithosphere and the asthenosphere.
The Internal Structure of Earth 5
The lower mantle is located between the upper mantle and the core.
Figure 1.3 Themantleisabout1800milesthick.
uppermantle(» 477miles)
lowermantle(» 1349miles)
Upper mantle
The upper mantle is composed of variety of rocks. One of them is peridotite, which is made up of minerals, olivine, and pyroxene. This layer includes all layers below the crust down to a depth of about 447 miles.
Lithosphere
Lithosphere, the upper part of the mantle, is about 60 miles thick. Like crust, it is made up of variety of rocks but it is cooler and more rigid.
Asthenosphere
Asthenosphere is located below the lithosphere. It is softer, hotter, and more fluid than the lithosphere. Asthenosphere carries broken large pieces of lithosphere on it. Its flow is part of mantle convection, which is the heat transfer from material to another material that occurs in the mantle.
Know More!
TheboundarybetweenthecrustandmantleiscalledMohorovicicdiscontinuityorMoho.ItwasnamedafterAndrijaMohorovičić(1857–1936),aCroatianmetreologistandgeophysicistwhodiscoveredMoho.
6 Earth and Space
ContinentalCrustlithosphere uppermostLayerofthemantle
asthenosphere
oceaniccrust
Figure 1.4 Theasthenosphereisthickerthanthelithosphere.
continentalcrust
Lower Mantle
The lower mantle is the layer found between the upper mantle and the core. It is made up of iron, magnesium, and silicate compounds. It is denser and hotter than the upper mantle. It is about 1349 miles depth and plays a major role in controlling the thermal evolution of the planet.
Core
Thecore isthedeepestandthehottestlayerofEarth found beneath themantle. It ismade upironandnickel.
The core is made up of two layers, namely, the outer core and the inner core. Some scientists believe that the metals in the core are in constant motion and that the inner core rotates faster.
Outer Core
The outer core is about 1400 miles thick. With a temperature ranging from 4000 °C to 5000 °C, the layer is so hot that the iron and nickel metals are liquid.
The outer core is very important to Earth as it creates the magnetic field. This magnetic field goes way out into the space and makes a protective barrier around Earth. It shields the planet from the Sun’s damaging solar wind.
Know More!
ThenamepyroxeneisderivedfromtheGreekpyromeaning“fire”andxenosmeaning“stranger”andwasgivenbyReneJustHaüy.
crust
mantle
outercore1400milesthickliquidironandnickel
innercore
The Internal Structure of Earth 7
Figure 1.5 The convection current in the outer coregeneratesthemagneticfield.
geographicNorthPole
geographicSouthPole
liquidinnercoresolidinnercore
magneticNorthPole
magneticSouthPole
Inner Core
The inner core is the innermost layer of Earth with a radius of about 759 miles. It has a temperature ranging from 5000 °C to 7000 °C. It is under immense pressure that the inner core is still solid even though it is hot.
Figure 1.6 Theinnercorerepresents1.7%oftheEarth'smass.
liquidcore
innercore
mantle
Know More!
In1936,DanishseismologistIngeLehmann(1888–1993)discoveredtheinnercoreandtheoutercoreofEarth.SheobservedthatseismicwavescreatedbyearthquakesonthesurfaceofEarthwouldbounceoffthetwocoresdifferently.
Let’s Do This!
8 Earth and Space
Purpose
Build a clay model of Earth
What You Need
red, orange, yellow, and blue claysrolling pinrulerknife or cuttermarble
What You Need to Do
1 Make a red clay ball that has a diameter of 30 mm. Set it aside.2 Using the rolling pin, flatten the orange, yellow, and blue clays. The
thickness of the orange clay should be at least 50 mm; the yellow clay should be at least 5 mm thick; and the blue clay should be 11 mm thick.
3 Cover the red clay with the orange clay. Make sure that the red clay ball is completely covered with the orange clay ball.
4 Cover the clay ball with the yellow one and then the blue one. Make sure the clay ball is completely covered before covering it with another layer of clay.
5 Cut the clay ball in half using a knife or cutter. Then insert the marble at the middle of the red clay ball.
Guide Questions
1 Roll the marble while it is in the middle of the clay ball. How does it affect the other layers?
2 If you move one of the layers in the clay ball, will it affect the other layers? How is this similar to the layers of Earth?
Let’s Review
1 What are the layers of mantle?2 Differentiate between the oceanic crust and the
continental crust.
The Internal Structure of Earth 9
1.2 Theories of DiastrophismDiastrophism (or tectonism) refers to the deformation of Earth's crust which leads to the formation of different landforms and other features.
The deformations are caused by Earth's movements, namely, uplift, subsidence, and thrust. Uplift refers to the movement in which the crust rises, while the subsidence is the sinking of the crust. Thrust refers to the horizontal movement of the crust. These movements are supported and explained by the theories of diastrophism—the theory of isostasy, the contraction theory, the convection theory, and the expansion theory. The descriptions of each theory are listed on the table below. Continental drift theory also is a theory of diastrophism. It will be discussed in chapter 2.
Theory DescriptionTheory of Isostasy The term isostasy comes from the
Greek ísos which means "equal," and stásis which means "standstill." The theory refers to the balance of the crust such that it floats and elevates on a denser material based on its density and thickness.
Contraction Theory The contraction theory states that Earth is shrinking through geological time. As it shrinks, the bigger chunks and blocks of crust are pushed downward; and they eventually sink. The lighter and the smaller chunks are then compressed and pushed upward.
Convection Theory The convection current theory states that the crusts and rocks are pushed by convection currents. As the rocks are pushed, they tend to move upward. This movement causes the folding and deformation in the crust.
Expansion Theory The expansion theory states that Earth is expanding in size and mass and that the distance of the continents from one another is increasing as well.
Know More!
AmericangeologistClarenceEdwardDutton(1841–1912)coinedtheterm‘isostasy’in1889.
10 Earth and Space
Let’s Do This!
Purpose
Demonstrate how land erosion affects the crust balance in water
What You Need
2 pieces of Styrofoam scissors glue a basin of water 1 cup soil
What You Need to Do
1 Cut an 8" × 8" piece and a 4" × 4" piece of Styrofoam.2 Glue the 4" × 4" piece on the top of the 8" × 8" piece.3 Place the glued pieces on the basin filled with water.4 Put 2 spoonfuls of soil on the 4" × 4" piece. Observe how the Styrofoams
balances on the water.5 Remove the glued pieces from the basin and move the soil to the
remaining part of the 8" × 8" piece. Observe how the Styrofoam floats in the water.
Guide Questions
1 How did the Styrofoam float when the soil was on the top of the 4" × 4" piece?
2 How did the weight of the soil affect the balance of the Styrofoam?
Let’s Review
Enumerate and explain the theories of diastrophism.
Key Ideas
The Internal Structure of Earth 11
Chap t er Summary
1 Earth is made up of three layers, namely, the crust, the mantle, and the core.
2 The crust is the outermost and the thinnest layer of Earth.
3 The mantle lies between the core and the crust.
4 The core is the deepest and the hottest layer of Earth, and it is found beneath the mantle.
5 Diastrophism refers to the deformation of Earth's crust.
6 Isostasy refers to the balance of Earth’s crust such that it floats and elevates on a denser material based on its density and thickness.
7 The contraction theory states that Earth is shrinking through geological time. The bigger plates are pushed downward, while the smaller plates are pushed upward.
8 The convection theory states that the convection currents in the mantle push the plates upward. This movement causes the deformation and folding in the crusts.
9 The expansion theory states that Earth's size and mass are expanding.
10 Uplift is the movement of Earth in which the crust is rising.
11 Subsidence is the movement of Earth in which the crust is sinking.
12 Thrust is the movement of Earth in which the crust is moving horizontally.
Concept Map
12 Earth and Space
Chap t er Summary
Earth
Crust Mantle Core
Continental Crust Upper Mantle Outer Core
Inner CoreOceanic Crust
Lower Mantle
is composed of
is divided into
Lithosphere
Asthenosphere
is divided into
The Internal Structure of Earth 13
Chap t er Tes t
I Multiple Choice Questions Choose the correct answer.
1 Earth's core is mostly made up of _____. A aluminumB magnesiumC iron and nickelD magnesium and copper
2 Which of the following describes Earth’s asthenosphere?A A rigid and hard solid rockB A gas under high pressureC A liquid at high temperatureD A solid that is able to flow due to
deformation
3 Earth's crust is made mostly of _____.A iron and nickelB iron and siliconC copper and nickelD oxygen and silicon
4 The lithosphere consists of ____.A the asthenosphere onlyB the crust and the entire mantleC the crust and the uppermost
mantleD the oceanic and continental
crusts only
5 The lithosphere and the asthenosphere are part of the ____.A atmosphereB coreC crustD mantle
6 The three main layers of Earth’s interior are _____.A the crust, the mantle, and the coreB the crust, the core, and the
lithosphereC the crust, the mantle, and the
asthenosphereD the mantle, the inner core, and the
outer core
7 Which of the following statements is NOT true about the continental crust?A It forms the continents.B It is up to 100 miles thick.C It can be found beneath the ocean.D It is thicker and less dense than the
oceanic crust.
8 Which of the following statements is true about the continental crust?A It forms the continents.B It covers 90 percent of Earth’s
surface.C It can be found beneath the ocean.D It is thinner and less dense than the
oceanic crust.
14 Earth and Space
Chap t er Tes t
9 The crust and the uppermost part of the mantle make up Earth’s _____.A asthenosphereB lithosphereC lower mantleD core
10 Which of the following statements correctly describes the core? A It permits plate motion.B It is the source of Earth’s heat. C It is a thin, cold, and rigid layer.D It helps in maintaining the
magnetic field.
II Structured Questions
True or False. Study each given statement carefully and determine whether it is correct or not. Explain your answer briefly.
_____ 1 The mantle is the thickest layer of Earth._____ 2 The Earth's interior consists of the crust, the mantle, and the core._____ 3 The theory of expansion shows gradual changes in the position of the
continents._____ 4 As you get closer to Earth’s inner core, heat and pressure increase._____ 5 The theory of isostasy states that the rocks form a higher region and slowly
rise while the lower region becomes heavier and slowly sinks._____ 6 The inner core creates Earth’s magnetic field._____ 7 The asthenosphere plays an important role in the movement of the
lithospheric plates._____ 8 Only the oceanic crust floats on the magma._____ 9 The mantle is primarily solid, yet it flows under certain pressure._____ 10 Earth’s lithosphere consists of the crust and the uppermost part of the
mantle.
The Internal Structure of Earth 15
Enrichment
Solve the problem.
What’s in the Box?
Liza returned home from school to find a box sitting on the kitchen table. Her best friend had come to visit her and brought her a present. In order for Liza to open the present, she had to tell her best friend at least three facts about it. She could do anything she needed to do to the box except open it to look at the gift directly. However, she should be careful not to damage the gift. How many facts do you think Liza can learn about the gift? How is Liza’s challenge related to earthquakes and to Earth’s interior?
16 Earth and Space
Making Connections
Technology
To study how a material behaves under vary-ing pressure, geophysicists use Diamond An-vil Cell (or DAC). This is a small chamber that has two polished diamonds. A sample of the material is placed between the two diamonds where it will be compressed. The pressure applied to the material can reach up to 6000 gigapascals. Since diamonds are also known to be transparent to some electromagnetic waves, spectroscopy and other diffraction techniques can be performed while the material is being compressed. However, due to small size of the stage, the size of the material to be analyzed is limited.
Environment
Basalt rocks are igneous, which means that they came from the lava that cooled down. However, they are not only known as the main component of the oceanic crust, but they are also used in many industries. Unknown to some, basalt rocks are used for construction and building of roads. They are also used as grinding stones for grains.
