Let's Do Science 2 – Text Book B

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Prr i ma P mary 2 Textbook

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The 5E Model – Guided Inquiry

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The Let’s Do Science series is based on the Biological Sciences Curriculu Curriculum riculu Study (BSCS) 5E teaching and learning instructional model. The he 5E E model is centered on the idea that students understand science concepts oncepts pts best by using prior knowledge to pose questions and find answers rs through hrough guided inquiry.

This hands-on approach, integrated with engineering ng g and design skills, sk s has students learn science by doing science. Teachers chers guide the llearning process and are able to assess student performance evaluating student mance ce by evalua explanations and the application of newly acquired quired d knowledge knowledg knowled and skills.

Engage

The Engage phase of the 5E model provides videss students with w the opportunity to demonstrate their prior knowledge and understanding of the topic or understand concept. Students are presented with which serves to h an n activity or question q motivate and engage students as they hey begin the llesson. Teachers identify and correct any misconceptions and d gather data dat from students which will guide informed teaching and learning. earning. ng Essential to stimulating and students is the use of mixed media d engaging gaging stude st such as colorful photos, illustrations found throughout the trations tions and diagrams d textbooks and activity books.

Let’s Science also includes extensive bo boo t’s Do S digital resources such narrated videos, interactive lessons, virtual labs, h as narra nar id slideshows and more. re.

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Explore

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This phase encourages exploration of concepts and skills through gh handshan on activities and investigations. Students are encouraged to work togethe together red learning earn and apply various process skills while gaining concrete, shared ch students experiences. These experiences provide a foundation for which epts.. This studentstuden can refer to while building their knowledge of new concepts. centered phase comes before formal explanations and d definitions of tthe concept which are presented by the teacher.

Explain

This phase follows the exploration phase and iss more ore teacher-directed. teacherteache Students are initially encouraged to draw on their learning experiences and earning ex e oncept ept through explanations e demonstrate their understanding of the concept and he opportunity pportunity to t demonstrate discussion. After the students have had the their understanding of the concept, the formal e teacher cher then introduces in definitions and scientific explanations. also clarifies any s. The teacher eache al erged during the th Explore phase. misconceptions that may have emerged

Elaborate

In the Elaborate phase, students nts refine ne and consolidate co c their acquired knowledge and skills. Opportunities for students to further rtunities nities are provided pro apply their knowledge and skillss to new situations in order to broaden si and deepen their understanding rst ng g of the concept. Students may conduct additional investigations, share information and ideas, or apply their ns, sh shar orm knowledge and skillss to other ther disciplines. d disc

Evaluate

This final phase se includes cludes both formal form and informal assessments. These can include concept models, journals as well as more traditional cept maps, physical phys ummative ative assessm assess forms of summative assessment such as quizzes or writing assessments. e encouraged to review and reflect on their own learning, and Studentss are on theirr newly wly acquired knowledge, kn understanding and skills.

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Let’s Do Science Let’s Do Science is based on the United States Next Generation Science Standards (NGSS). The series consists of full-color textbooks and full-color activity books for Grades K to 6.

Birds

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Birds are anim covered in feat legs and two w their wings to f

Let’s Do Science engages students with a highly visual al presentation of the disciplinary core ideas in the textbooks xtbooks books and places an emphasis on applying scientific knowledge nowledge ledge using NGSS practices through numerous scientific tific investigations. Let’s Do Science sees engineering ring ass an essential element of science education and tightly d as such is tight integrated into both the textbooks and activity ctivity books.

Birds ha shapes shape o bird to

The Let’s Do Science textbooks include e the following ffeatures:

Think Deeply

Topic-related questions for group discussion aimed at deepening students’ understanding of the topic.

d In the Field

apes o all shapes e plants of If you love and sizes,, you might want to be a rist. A horticulturist iss a horticulturist. in growing spec hat specializes scientist that us eople to use. plants for people

Horticulturists can also use their knowledge of plants and soil to help manage and protect natural areas like parklands or nature reserves.

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l knowle know Horticulturists use their knowledge m im armers improve farmers help fa of o plantss to he eg ege vege v and vegetables ers and ffl wers flo uits,, flowers uits ruits the ffruits, o ow grow gr g h y grow. they

Engineer It!

Goes beyond inquiry uiry by encouraging students udents to design, model and build olutions to to engineer solutions oblems. defined problems.

In the Field

Inspirational sc sciencerelated to ated professions p stir interest rest in sciencerelated careers.

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A Closer Look

Rainforest Layers

Tropical rainforests are the most diverse land habitats on Earth. They are warm all year round and lots of rain means lots of water for living things. There is another reason tropical rainforests are so diverse – layer 53 s.

Tropical rainforests have four main layers – the forest floor, understory, canopy and emergent layer.

Each layer forms a habit at for different types of plants and animals.

You can think of a tropical rainforest as four habitats in one!

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A Closer Look

Invokes enthusiasm in science by presenting interesting topics beyond the syllabus.

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Amazing Fact!

Interesting facts to bui build interest and enthusiasm. nthusiasm.

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Birds reproduce by laying eggs. Parents often care young when they for their you hatch from the eggs.

mals with a body thers. They have two wings. Many birds use fly.

Did You Kno Know?

ave beaks of all and sizes. The ps the help k helps of the beak . n d it needs get the food

Did You Know?

All birds have feathers and wings, but not all can fly. Flightless birds include penguins, emus, ostriches and cassowaries.

AB

Try This!

Activity 2.3

Optional ptio hands-on activities to be conducted activ in groups or at home.

What are the characteristics of birds?

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Science Words

volcano erupt magma lava earthquake tsunami

flood landslide thunderstorm wildfire hurricane

4. What process is show n in the

tornado weathering erosion deposition land reclamation

Review

1.

Which best describes the process when soil and rocks fall from mountains and hills. (a) Tsunami (b) Wildfire (c) Landslide

2. Which best describes the process when hot molten rock flows onto the Earth ’s surface? (a) Earthquake (b) Volcanic eruption (c) Thunderstorm 3. What can cause a tsunami? (a) Earthquakes and volcanic eruptions (b) Landslides (c) Hurricanes and torna does

5. Describe the differ ence betw etwe een en erosion and weatherin g. eros r ion

to label bel the picture.

deposition

AB Activity

Links students to the Let’s Do Science Activity Book at the appropriate juncture.

(b)

(a)

7. Desc scrib ribe e the difference betw een a landslide and weathering.

Discussion

8. List three processe s that chan cha ge the shape of the land rapidly.

Emergent Laye err

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picture?

(a) Erosion (b) Weathering (c) Deposition

6. Use the words in the box

Extra ra information to t build students’ dents’ knowledge know se of the cu base current topic.

9. List three process that change the shap e of the land slowl owly. y.

10. Describe two ways people can slow or preve nt changes to the sshape of the land.

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Canopy y

Topic-related questions and situations for class discussion to build a deeper understanding of topics.

Un rstory Unde

Review

Science Words

Forest Floor

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Topical questions at the end of each chapter for formative assessment.

Lists the essential science vocabulary covered in each chapter.

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Contents

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Unit 5 – Earth’s Land and Water Earth’s Landforms Earth’s Water Salt Water on Earth Fresh Water on Earth Liquid and Solid Water ping g tthe he E arrth Mapping Earth ew Review

Unit 6 – Forces and Motion

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Position and d Motion Motio otio o on n Forces and Motion rces Types of Forces Review w

Unit 7 – Properties Propert of Matter What Is Matter?

M Stat of Matter States Des Descr uring Matter Ma atter Describing and Measuring Properties of Materialss P Re Review

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2

4 12 14 17 22 24 34

38 40 4 4 44 4 48 5 54

56 58 60 68 72 78

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Unit 8 – Changes to Matter Cha Changing Matter Hea at and Matter Heat Rev view Review

Unit 9 – Heat and Electricity lectricity What Is Heat? at?

Sources of Heat at Using Heat mper Heat and Temperature Using ng Electricity Electric lectr ple Circuits Circuit Simple Review ew

84 92 100

104 106 107 110 112 114 118 120

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Earth’s Land and Water

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In this chapter you will ...

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• list and describe different kinds of land and bodies of water.

• identify where water is found on Earth and whether it is solid or liquid.

• develop a model to represent the land and bodies of water in an area.

What are the Earth’s different landforms andforms and bodies of water?

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uc Go Online!

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Access interactive content relating to this topic on the NGScience website. ngscience.com

What iis a map? are maps useful to people?

How a

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How can you describe the he land around you?

Earth’s Landforms forms

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The shape of the ssurface urface o ur off the th Earth can be different ffere rent iin n many ma ways. In some areas ea reas eas tthe he land la is flat. as the the land and m In other areas may be hilly or surrounded nded db by mountains. m mou o

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The different shapes of the Earth’s land are called landforms.

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What are some landforms in your area?

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Amazing Fact!

A mountain is a very high area a of of land that rises above the land d around ar nd it. Mountains are usually steeper and eeper a n taller than hills.

The highest part of a mountain mounta is me moun called the peak. Some mountains ed in snow sno for all or have peaks covered part of the year.r.

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A series of mountains close together is called a mountain range. The longest mountain range on Earth is the Andes in South America. It is about 7,000 km g (4,300 mi) long.

Mountains

Think Deeply ep

You are planning g an e peak pea expedition to the of a tall mountain. What things will you pack?

Why??

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Parts of a Mountain A mountain has different parts.

Many mountains have a base, slope, snow line and a peak.

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A Closer Look

The top and a highest part of a mountain m is called the peak, or summit. summ

The slope is the side of the mountain. The slope reaches from the base to the peak.

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The snow line is the place on the mountain above which snow can be found all year round.

The base is the th he part of a w whe er the slope mountain where meetss flat or hills. flat ground fl gro The base ba is usually the w pa of a mountain. widest part

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Hills, Valleys and Plains A hill is an area of land that att is is higher than the surrounding ding land. Hills are usually no not ot as tall ta all or in n steep as mountains.

hill

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Often, many hillss can can be be found in am ak king the land the same area making look bumpy.

How w are mountains m and nd hills ssimilar?

How ar are they different?

Did You Know?

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Scientists often classify mountains as landforms that rise 300 m (1,000 ft) above sea level. Landforms that are shorter are usually called hills.

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pla plain ai n

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valley

A valley is a low area that lies between hills or mountains.

Valleys are often formed from the weathering and erosion of rivers.

A plain is a large area of mostly ostly flat land. Plains are the most common mmon landforms on Earth.

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Amazing Fact!

The Yarlung Zangbo Grand Canyon in Tibet, is the deepest canyon in the world. It was formed over millions of years by the erosion of the Yarlung Zangbo River. At some points, it is more than 6,000 m (19,685 ft) from top to bottom.

Canyons A canyon is a deep and often n p rocky cky narrow valley with steep ually y formed sides. Canyons are usually nd erosion of o by the weathering and treams and rivers mountains by the streams h them. em. Weat that run through Weathering ter, when ice also occurs in winter, cks breaks apartt rocks. mation on of can ca an The formation canyons from erin ng and erosion ng ero er weathering takes nss of of years. years. millions

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Observe rve and com compare lan the Earth’s landforms on the NGScienc NGScience website.

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Plateaus

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piece ce A plateau is a large flat piece bove tthe he of land that is raised above ateau aus can can an o surrounding land. Plateaus often ountain untain peaks p be found between mountain any an or at the top of canyons.

How is a plateau similar to n? How is it different? a plain?

AB Activitie Activities 5.1 – 5.2

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Earth’s Water

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Water is important to all living ving nd things. Plants, animalss and people need waterr to survive. ere would be b Without water, there no life on Earth. e water on Earth Ea E Some of the is er. It can be found f fresh water. in s, rivers vers and llakes. streams,

Why hy is water w important to all living things? Where can find water on Earth? we fin

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Most of the water on Earth is in the e ocean. The ocean contains salt water. ater. ter on The fresh water and salt water Earth can be found as liquid water or o solid ice.

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Salt Water on Earth The Ocean ean and an Seas When en viewed viiewed d ffrom ro space, the Earth oks llike ike a big big blue ball. The blue looks p arts y ou ssee e are the ocean. The parts you ocean iiss a large body of salt water. ocean It covers covers almost three-fourths of the su ce of the Earth. surface grea diversity of living things A great liv iin the ocean. The ocean is live als very important to people for also t transportation and sources of food.

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Salt water can also be found in seas. A sea is a smaller part of the ocean that is partly surrounded unded by land.

In some cold areas of the e Earth, Eart rth, parts of the ocean can n freeze freeze into int nto lid salt salt water. water wa sea ice. Sea ice is solid

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Lagoons

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A lagoon is a shallow body yo off sa ssalt alt rom tthe he sea sea water that is separated ffrom ock or or other othe or the ocean by sand, rrock natural barriers.

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Fresh Water on Earth h The water in the ocean is too salty salty ty for most living things on land d to o use. he e water They need fresh water. The sh water we drink is fresh water. Fresh contains very little salt.t. can an be found fo f On Earth, fresh waterr can s, llakes ak and nd p in streams, rivers, ponds.

In cold areas, fresh resh water water can also so olid ice. ice. e. be found as solid

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Streams and Rivers A stream is a flowing body dy y of of fresh fressh water. A stream starts att a high high ta ain n or or hill. hill. As As point such as a mountain m, itit may may pick pic ick up it flows downstream, more water from melting meltltin ing snow snow or oin o ther sstreams tr rain. It may also jjoin other er to to form form a river. and grow larger

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Like streams, mss, rivers riv ve ers are are fresh water dow owns nsttream rea am Rivers flow and flow downstream. es or or the the ocean. oc into lakes

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Ponds and Lakes

Rivers often flow into lakes. A lake is a large body of fresh water that at is surrounded by land. Lakes are re reation, ion, often used by people for recreation, transport and as a source of of drinking water.

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ond is is a closed close Much like a lake, a pond body of fresh water. Ponds Ponds are are ar usually smaller than a lakes. kes.

How is a lagoon agoon different dif p from a lake or pond?

Amazing Fact!

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Lake Michigan in the United States of America is the largest lake located inside one country. It is almost 500 km (300 mi) long!

Go Online!

Observe and compare the Earth’s different bodies of fresh water on the NGScience website.

QuickCode: P6J2

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Glaciers A glacier is a large body of thick hick k d--up of ice that forms from the build-up rs. snow over many years. and. nd. They They m Glaciers form on land. move nm ountai o untain nss very slowly down mountains. erss g et lo et owe wer down a When glaciers get lower hey ey m ay melt m into rivers mountain, tthey may s. S ome g om lac la and lakes.

Some glaciers reach the nd fo fform orm rm iicebergs. ce ocean a and

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Icebergs

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An iceberg is a large body of freshwater ice floating in the ocean.

Most icebergs form when chunks of ice break off a glacier or ice shelf.

A small iceberg is about the size of a bus. Some icebergs can be over 100 m (300 ft) in length.

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Watch how g glaciers form icebergs on the NGScien NGScience website.

QuickCod QuickCode: P7Z5

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Go Online!

Scientists have discovered that human activities are causing temperatures on Earth to rise. This is causing ice at the Earth’s pole to melt faster than normal.

Find out more about the effects of climate change on the NGScience website.

QuickCode: N7C4

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Liquid and Solid Water Wate There are many places where ere water can be found on Earth. th. Salt Salt water fills the ocean. Fresh sh water wate ater er ri ers and flows from streams to rivers lakes. the he Earth, Earth, water w In cold parts off the is tate e as as solid solid id ice. If the in a frozen state temperature warm ure gets wa ar enough, the ice will m melt elt into water. w

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In some places, streams, rivers and lakes may have water in the warm months of the year and ice in the cold months of the year.

Each year, the pattern of changing ng g from water to ice and back to water repeats.

AB

Activities 5.3 – 5.4

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Mapping the Earth Try This!

Look at a globe or map of the Earth with a classmate. Which parts are land? Which parts are water? What landforms can you see?

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What Is a Map?

A map is a drawing or model del of an area. Some show a large rge area.

A globe is a map of the he whole e are also maps m ma of planet Earth. There countries, cities and towns. ow smaller a Maps can show areas such as you home. a park, zoo or even your

Maps are very useful. They show us the types of things in an area. Maps also show the location of things and the distance between things.

How do people use maps?

How are maps useful?

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Maps can tell us the location of different landforms and bodies of water in an area.

canyon

plateau au

lake pond

hills beach

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mountains

Discuss the different bod of landformss and bodies n the map. m water on Describe cations of the landforms the locations o water. and bodies of

river

valley

plain

ocean

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Parts of a Map

Find a map of a park in your area. What are the parts of the map? What does the map show?

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Try This!

What things can you learn from the map of Silverlake Park?

Maps have different nt parts that help h people to read and nd understand understan nderstan them.

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ave a title th Many maps have that describes what the map ap shows.

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Maps are much smaller than the areas they represent. A scale is a way to compare the sizes and distances of things on a map with the actual sizes and distances in real life.

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Activity 5.5

Try This!

Draw a map ap to show sho y the thingss around your e. Include a key home. and a scale.

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Maps can also have a key. A key explains what different things on the map mean or represent.

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Many cars have maps called navigation systems to provide drivers with wi directions.

How We Use e Maps Map Maps are very ry useful. usefu We use maps to find the locations location of things in places we do nott k know now about. a A map a driver find a street map can n help h or help reach a waterfall. help p a hiker h

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A map can help you find the e tiger enclosure at a zoo orr the the sports store in a mall.

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Maps also tell us the types e ty ypes pes a and nd location of things in an n area. area.

We can use maps when visiting pss w p visit o help ellp us us ffind the natural areas to location of different ffe erren ent landforms la and ndfor or types off water a er in in the the he area. ar AB

Activities vities 5.6 – 5.8

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Use the information in the map to describe the park.

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Science Words

plateau salt water ocean lagoon freshwater

river lake lacier glacier iceberg map

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landform mountain hill valley plain canyon Review

1.

pare mountains mo Draw a Venn diagram to compare and hills. mountain

hill

2. Draw a Venn diagram to compare plains and plateaus. pplain pla lai

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plateau

3. Draw a Venn diagram to compare glaciers and sea ice. sea ice

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glacier

4. Use the words in the box to label the e landforms. landfor canyon (a)

(c)

plateau

plain

valley

(b) b)

(d)

5. List two ways people use maps. peo 6. Which part of o a map tells you the distances between o objects? (a) Key (b) Title T (c) Scale Sc 35

A Closer Look

The Grand Canyon The Grand Canyon is a very steep and long canyon found in Arizona in the United ed d States of America.

The Colorado River has been weathering he ering and eroding the canyon for more than than me, itit has has as five million years! During that time, the world. world. formed the largest canyon in the

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Go Online! ne!

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The Grand Canyon is over 445 km (277 mi) in length. In some parts, it is almost 1,800 m (6,000 ft) deep and up to 28 km (18 mi) across.

Weathering and erosion continue to make the Grand Canyon deeperr fo or and wider, but much too slowly for us to see from day to day.

Take a virtual fie field trip to o the amazing am Canyon on the Grand Canyo NGScience website.

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nd What do you think the Grand lion on years years Canyon will look like a million from now?

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Forces and Motion

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6

In this chapter you will ...

• describe the position and motion of objects.

• identify pushes and pulls.

act forces.

• distinguish and describe contact and non-contact • describe how friction, magnetic force and gravity can affect the motion of objects.

How can we describe the position and motion of objects? objec

Go Online!

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Access interactive content relating to this topic on the NGScience website. te. ngscience.com m

How do forces affect motion?

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Wha is the difference between What co contact and non-contact forces?

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Position and Motion When describing the world around ound us it helps to know where things gs are a e and and how they are moving.

Describing Position sition The position of an object object is i its esc be the location. We can describe bject by b saying position of an object where it is relative objects. ive to t other o

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Let’s describe the positions of some of the objects in the room.

The plant is to the left of the computer. nt and The computer is between the plant the books.

The clock is above the plant.

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n front of The keyboard is in the computer.

What hat are some so other ways describ the positions of to describe the objec objects?

AB

Activity 6.1 A

Try This!

With a partner, describe the position of your desk relative to other classroom objects.

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Describing Motion

Go Online!

Observe and describe different objects in motion on the NGScience website.

QuickCode: F1T2

When an object is in the process cess of of viing changing its position, it iss moving. e can can We say it is in motion. We n of of an no object jec in describe the motion different ways. be motion by talking We can describe about the path which it ath h along along wh alo w h is moving. an m ove iin n a straight line.

Things ca can move ma ay roll, roll, turn tur or spin. Things They may n mov ve up up and a down, back and can move orth orr round round and round. forth

Describe the different ways things move in a playground.

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We can also describe the speed of an object in motion. Speed is how fast or slow it is moving.

Activity 6.2

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AB

Describ the motion of Describe ass passengers on a roller coaster du during a ride. How does the speed of motion change?

Try This!

Choose a ball sport.

Describe how forces are used to change the motion of the ball.

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Try This!

Forces can make an object change shape.

Plan and conduct an investigation to see how different forces can change the shape of a piece of clay.

Forces and Motion n A force is a push or a pull.. A push push ething away away is when you press something en you you tug tug from you. A pull is when you. something closer to you. can change chang the Pushes and pullss can obje ject cts. movement of objects.

Ap push ush fforce o applied to a wheelbarrow makes it move. w whe heel elb A ssuitcase moves when you use a pull force to drag it be behind you.

In what ways can forces change the movement of an object?

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Sometimes, like when riding a bicycle, we use a push and a pull. hen we We use pushes and pulls when vacuum a floor or open and close a door.

What push and pull forces can you observe around you? How do they make things move?

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Activities 6.3 – 6.5 45

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Force can make things move in different ways.

How do forces change the movementt of a ball b during a soccer match? matc

Try This!

During uring a game gam am of soccer, a kick kic ck starts starts rts tthe h ball moving.

A lla ayers er pass the ball, it Ass p players eds up, slows down and speeds changes direction. When c ha catches the the goalkeeper the go b all, itt stops moving. ball,

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With a partner, use forces to make marbles move in different ways. Describe the forces you used and how it affected the motion of the marbles.

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at

As we can see see ffrom rom a soccer match, forces an object: orces can can make m

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art a ar nd stop stop moving. m • Start and • Speed Sp pee eed up up and and slow down.

• Change direction.

Change nge d ire AB

Activity 6.6

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ed uc ati on Types es of For Forc Forces

There e are different differe types of forces. rcess that are applied when objects Forces are tou uching are called contact touching forces ces. s. Hit Hittin forces.

Hitting a ball and pulling on a pe ea rope forces. are contact c

Som forces can be applied when Some objects obj s are not touching. These forces ac at a a distance and are called act non non-contact forces.

Take a magnet and hold it above an iron nail. The force of the magnet is applied to the nail without touching it. The force of a magnet is a noncontact force.

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Friction

Take a wooden block and slide it along the floor. The wooden block moves when you push it. It then slows owss down and stops.

What causes the block to o slow down and then stop?

Friction is a contact force orce e that slows slow down moving objects. s. It occurs when two objects are a in n contact contac with each other. The friction rictio between we the surface of the block ck and the th surface of the floor caused to slow aused ed the block bl p. down and stop.

Try This!

Given the same force, wo would a wooden block move further on a wooden floor or carpet?

Plan and conduct an investigation to find out.

Think Deeply

What are some examples where friction can be helpful? When can friction cause problems?

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Magnetic Force Think Deeply

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What do you notice about bou the objects attracted d to the magnet?

Why are the paper clips attracted to the magnet?

Try This!

A ma magnett is mag i an object bj t that th t can certain types of metal – it has pull c cer magnetic force. Magnetic force is m magn non-contact force. It works over a a no distance. A magnet does not need to d di be touching the object it pulls.

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In small groups, gather some objects in your classroom that you think will be pulled by a magnet. Use a magnet to test each object.

Engineer gineer It!

Design and nd build a toy car thatt can move up own a ramp using us and down tic forc magnetic force.

What are some ways magnets are used by people?

AB

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Activity 6.7

A Closer Look

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The Poles of a Magnet

Magnets have two poles – a north rth pole and a south pole.

The pulling force of a magnet is es. strongest at the poles.

Magnets can attract (pull) pull)) her or repel (push away) other magnets.

When the opposite poles of to ogether, o two magnets are brought together, the magnets attract each other. h oth th her her.

wo magnets mag magn gnets When the like poles of two e magnets mag magn nets are brought together, the repel p each other.

Try This!

Take two bar magnets and put the poles together in different ways. Describe what you observe.

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Gravity

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Use your finger to trace the path ath the basketball will take as it leaves es the th boy’s hands.

What force causes auses the ball ba to the air? air to move up into What force will cause the o the ground? gro ball to fall to All objects attract other objects. tract othe This force is called gravity. gr

The boy used a push force to throw the basketball and the Earth’s gravity pulled the ball down to the ground.

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When you drop a pencil, it falls to the ground. When a skydiver leaps from a plane, they are pulled to the Earth’s surface.

Try This This!

All of the objects on Earth are being pulled downwards towards the center of the Earth by gravity. The Earth’s gravity keeps everything on its surface and stops things from floating away.

Activity 6.8

a

AB

In n small grou groups, go and throw a ball outside a nto the air. Describe into how forces, including rav affect the gravity, mo motion of the ball.

Think Deeply In what way is gravity similar to magnetic force?

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Science Words

push pull contact force non-contact force

friction tic force magnetic avity gravity

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position motion speed force

Review

1.

Which best describes position? (a) How far an object has moved. d. (b) The location of an object. (c) How an object moves.

eed?

2. Which best describes speed? (a) The location of an object. (b) The path along which a an object moves. (c) How fast or slow an obje object moves. scribes motion?

3. Which best describes (a) The movement ement of an object. eed of an object. (b) The speed orce of an object. (c) The force

f 4. Whatt is a force?

Li t two activities ac 5. List where you use a push force. tw activities where you use a pull force.

6. List two

54

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7. List five ways forces can change the motion of an object. act force. force 8. Describe and provide an example of a contact 9. Describe and provide an example of a non-contact force.

10. What force pulls the pins to the magnet? gnet?

t 11. True or false. Friction helps things move.

12. What force is pulling tthe boy to the water?

55

Properties of Matter

n

7

In this chapter you will ...

• describe and classify matter.

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a

• test and describe the properties of materials.

What are some ome properties of matter and materials? mat

Go Online! line!

Access interactive tive content relating ing to this topic pic on the NGScience cience website. ngscience.com science.com

56

What properties of objects make them suitable to their use?

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What Is Matter?

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Everything around you is matter. er. The things you see, touch, smell and taste nk is are matter. The water you drink the he is matter matte matter. The air you breathe ma too. Matter is anything that has mass and takes up space.

What matterr can you see around you? Is there re matter around you that you cannot see? se The soft to toy takes up space bucket. The beach ball in the bu takes u up more space than the toy c car.

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ed uc at

Water, rocks and air are matter.

Some matter can have more mass ss than other matter. Using a balance, balanc we can see that the teapot ot has more mass than the mug.

Try This!

Compare some different objects in your classroom. What words can you use to describe each object?

59

States of Matter

tio n

Compare the things on n these y differen pages. How are they different?

Matter can come in different diff ifferent ferent states sta – solids, liquids and g gases s. gases. ases sess.

The toy blockss are a e solid matter. m ma

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Wate id matter.

Water is liquid

ed

The air a inside nside sid the bal side balloon is gas gas.

AB B

Activity 7.1

61

ed uc at Solids

Take an eraser and roll it on e. Does the th shape of a table. the eraser c change?

Think Deeply

Solid id matt mat matter has a shape of its own.

T amo The amount of space solid matter take up does not change. takes When you rolled the eraser on the table, the shape and amount of space taken up by the eraser did not change.

a

Find three things in your classroom that are solid matter. Tell how you know they are solid matter.

The eraser, aser, like m most of the things you ee around ound yo see you, is solid matter.

Ice is solid water.

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ca t

The toy blocks are solid matter. They hey keep the same shape when they y are e in the container or spilled out.

AB

e

toy The amount of space the to oy blocks take up also stays the same.

Activities 7.2 – 7.3 .3

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Liquids

ion

What happens to the shape of the water as the girl pours it anoth from one containerr to another?

Try This!

Pour some water between different containers. Describe what happens to the shape of the water.

Think Deeply

tter does doe not have Liquid matter pe of its own. own A liquid ow a shape ws to o take the shape of flows e container ntainer iti is in. the

a

A pile of sand appears to change shape as it is poured from one container to another.

Is sand a solid or a liquid?

Explain your answer.

The colored water the he girl d matter. is pouring is liquid ured from As the liquid is poured o another, another its one containerr to shape changes. nges. s.

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ga le du ca tio n

Pour some water into a beaker.

Observe how much space the water takes up. Pour the water into another container, then pour it back into the beaker. What do you notice?

Like solid matter, the amount of space taken up by a liquid does not change.

Did You Know?

The amount of space something takes up is somethin called vo volume. You can measure the volume of meas liquids with a measuring qu cu p or beaker. cup

Tell how you know milk is a liquid.

AB

Activities 7.4 – 7.5

65

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When air is let out of a balloon, it spreads out to fill the room.

Gases ses

Blow ow up a ballo balloon and hold itt closed.

Observe the shape osed. Obs and a nd size o of the balloon.

S Slowly le let the air out of balloon. What do you tthe ba ball observe about the size and o obser sshape of the balloon? sha

The air in the balloon is a gas. Gas is matter that does not have a shape off its own. It spreads out to fill the space it is in.

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Try This!

Blow some soap bubbles.

Talk about the shape and size of the bu bubbles. What happens to the air in the when they pop? bubbles w

Think Deeply

Gases can also change in the he amount of space they take up.

When you let the air out of the balloon, it spreads out ut to o fill the room. It takes up u more re space. spa

A scuba tank can hold enough air for a diver to breathe underwater for more than an hour.

Why is this so?

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al ed uc at

Properties of Matter

Describing ibing and asuring Matter M Measuring Describing scribing Matter M

We can descr W describe and compare the around us by observing objects o cts arou their properties. their prope We can observe some properties, W ca such ssu as shape, size and color, using our our ssense ou sen of sight.

What are some of the properties of the objects on these pages?

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Try Thi This!

Use your sense o of observe touch to obse different obje objects in your classroom. Describe the classroom texture of each object. exture o

You can also observe the properties roperties of objects using your sense nse of touch. touch Texture is how an object ect feels.

An object might feel hard soft. ard rd or so It may feel rough h or smooth. sm h AB

Activity 7.6

69

Measuring Matter Use a balance to compare the weight of the objects on your table. Order the objects from the lightest to the heaviest.

Compare the soft toy and the soccer ball. Which ass? object has more mass? now?

How do you know?

du ca tio n

Try This!

There are many properties perties of objects you can test or measure. balance easure. A b is a tool you can the an use se to measure me weight of an n object. object bjec Weight is how ow light or o heavy somethi hing is. something AB

R

The socce soccer ba ball is hea heavier than the ft toy. soft

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Activity tivit 7.7

e used Rulers and tape measures can be to measure the length of objects in centimeters or inches.

ed u

eti by etic You can test if an object is magnetic gn netic tic holding it near a magnet. A magnetic object is pulled by the magnet.t.

R

y of an object objec ect You can test the buoyancy me objects objec cts by placing it in water. Some n placed d iin stay on top, or float, when water. Other objects fall to the bottom, b bo ottom, or sink, when placed in water.

AB

The nails are mag magnetic.

The T rubber duck duc floats. The ma marbles sink.

Activities 7.8 – 7.9 71

Properties of Materials ria We use different materials to make erials different objects. Some materials ood, d, plastic, include metal, glass, wood, rubber and fabric.

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Go Online!

Learn about different materials and their properties on the NGScience website.

QuickCode: P9G5

Try This!

Find objects in your classroom that are made of two or more different materials.

How are the materials suited to how the objects are used?

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ave differ Different materialss have different en we make objects, o properties. When it o choose oose materials ma is important to that rtiess that are suited and have properties ow the object objec is used. safe for how What materials mate are used to these objects? How are make thes of the objects the properties prop suitable to their use? suitab

eg al

The strength of a material is how much it can be pulled apart or Strength goes here. eaking. pushed together without breaking.

Flexibility goes here. mate Hardness is how much a material atc can withstand scratching.

Why is metal etal a suitable suit al for making mak material b thingss such as bridges, mers and nails? hammers

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Flexibility is how how much m ch a material can bend an b en nd without breaking. The he rope rope is made rial tthat hat is flexible of material and strong. ong.

What are some other objects that are flexible? What materials are they made of?

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ti

Re ga le du ca

Transparency is how much light can an pass through a material. The glasss jars are transparent. You can see ee the he food inside the jars clearly.

The white curtains allow some ome me light to translucent nslucen pass through – they are translucent.

You can see through the he curtains, but b not clearly.

oes no n ow any A material that does not allow light to pass through You rough ugh it is opaque. o op cannot see through hrough ugh opaque opaq materials.

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ca tio n

Absorbency is how ho much m liquid a nh old material can hold.

mes, like like when w Sometimes, cleaning a spill, it iss useful ful for a material to be orbent absorbent.

Other times it is helpful to use materials that are not absorbent, like the plastic used to make an umbrella and a raincoat.

AB 76

Activities 7.10 – 7.11

Engineer It!

tio n

Design and d build yo your own elect mate object. Select materials d on how su based suitable and safe they are for the the object. function of th

R

Discuss the materials used to make these objects.

How are the materials suitable and safe for how the objects are used?

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Science Words

magnetic buoyancy float sink strength hardness

y flexibility arency transparency ansparent transparent anslucent translucent opaque absorbe absorbency

Re ga le du ca tio n

matter solid liquid gas texture weight

Review

1.

Which best describes matter??

an see. (a) Everything that we can (b) Everything that has mass and ttakes up space. el (c) Everything we can feel.

2. True or false. (a) Solid matter has a shap shape of its own. ter ha (b) Liquid matter has a shape of its own. ead out to t fill the container they are in. (c) Gases spread

perty tells you how light or heavy an object is?

3. What property ht (a) Weight oyancy (b) Buoyancy trength (c) Strength

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4. What property tells you if an object floats or sinks? (a) Flexibility (b) Buoyancy (c) Transparency 5. What property tells you how much lightt can pass through a material? (a) Transparency (b) Weight (c) Hardness

liqu a material 6. What property tells you how much liquid can hold? (a) Transparency (b) Strength (c) Absorbency eac object.

7. List some properties of each (a)

(b)

(c)

(d)

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In the Field

If you love art and science, you might want to be an architect. An architect designs and draws plans for structures like buildings and houses.

R

ed

Architects know a lot about materials and their properties. They need to make sure the materials used to build the structures they design are n. safe and suitable for their function.

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Being an architect can ca be a very rewarding arding job. You Y design the places where here people live, work or play. If you were an architect, what would you u design? desi

81

Changes to Matter

ed u

n

8

How can an object made of a small set of pieces be disassembled sassembl and made into a new object?

Re ga

In this chapter pter you will ...

• describe ways ys in which matter m can change. e how an object made of a small set of pieces can • describe ssembled and made into a new object. be disassembled

ob rve, test a • observe, and describe how heat can change matter.

som changes caused by heating or cooling that can • list some ever be reversed and some changes that cannot be reversed.

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uc

Go Online!

Access interactive content relating to this topic on the NGScience website. ngscience.com

How does matter change when it is heated or cooled?

83

Changing Matter

on

How Can We Change Matter? tter?

y ways.

We can change matter in many any ways wa aper by You can change a sheet of paper ake a new object. o folding or cutting it to make

What are some other ways we can change matter?

84

le du ca

You can change matter by breaking king g it into smaller pieces, like cutting ga loaf of bread.

You can also change matter terr by putting smaller pieces together ogether her to make a big object, like e assembling ssembling the parts of a toy.

AB

Try This!

Does the mass of solid matter change when it is cut into pieces? Conduct an investigation to find out.

Activity 8.1 81

85

ed uc ati

Sometimes times es when w we change ter, we can also a change it matter, ck to its original origi back form. You change mat matt matter when you blocks to build a toy assemble b house. You h Yo can also take apart Y th he toy house, leaving the the b bloc blocks again.

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Other times, matter that is changed cannot be changed back to its original form.

AB

Activity 8.2

uc a ti

When you chop firewood, you cannot change it back into a log.

When you make a fruit smoothie, you cannot change the smoothie back into the fruits used to make it.

What att ar are e some s other examples where matter example les w is changed chan cha anged da and cannot be changed change ch ed back?

Try This!

Take a piece of scrap paper and change it in a way that it can be changed back. Change the paper again in a way that cannot be changed back.

87

Putting Together and Taking Apartt Different objects can be be made by putting smaller smalller he er. Th he n ew objects together.

The new ave differ objects can h have different characteristics, even cs e ven though ade off the same they were m made ece es. set of pieces.

Think Deeply

eg a

Imagine you are a builder about to build a art new house. Which part of the house would you yo build first? Why?

88

ati o Many bricks riick ca can a be put her to m together make the walls of a ho o se. house.

89

a

Imagine you are a builder about to demolish an old house.

Which part of the house would you take down first? Why?

du ca tio n

Think Deeply

An object such as a house is made of many small pieces. The pieces can be disassembled and made into new objects. The bricks used to build the walls of a house can be disassembled.

90

du ca tio n

The disassembled bricks ks c can an be assembled again and d made made into new objects.

They could be u used sed to to make k a or to to build build uild garden path or ep it. a barbecue pit.

R

wo bjects can can have ha The new objects en nt characteristics, characteris cha isti even different ugh they they were were re made m though of the same me sset et of of pieces. piece AB

Activity 8.3

91

Heat and Matter Learn about different materials and their properties on the NGScience website.

QuickCode: E1X9

Changing Temp Temperature ure

ca tio n

Go Online!

Temperature is how hott orr cold something is. When matter is heated, its temperature temperatture ure increases. increase When matter is coo oo cooled, oled, ed, its decreases. temperature decr crea ea ases.

Heating and cooling c oling g matter mat matt can cause it to change c ng from fro f one state another. to another er.

What cha change ange in state occurs solid matter is heated? when so m

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ed uc ati

Butter melts when it is heated.

Solid to Liquid

When metal is heated, it changes into heate heated liquid. a liq liqu

When matter is heated, its temperature increases. s. This can can ge from rom om solid to cause matter to change ed melting melting. g. liquid. This process is called Some matter, like ice,, will will melt at anges ffrom room temperature. It changes q water. Other water h matter her solid ice to liquid water. requires more requiires m ore heat heat to start sta melting. star meltiing g.

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Try This!

Plan and conduct an investigation to observe how heating and cooling changes a block of chocolate.

Describe the changes you observe.

Liquid to o Solid olid

When matter atter er is cooled, coole its rature decre decrea temperature decreases. This can e matter to c cause change from liquid to d. This his proc proce solid. process is called freezing.

Placi P ciing wa wate Placing water in a freezer decreases its te emper temperature.

It changes from liquid wate w water to solid ice.

What causes a wax candle to melt and freeze?

AB

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Activity 8.4

Reversible Changes

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The change from liquid water to solid ice is an example of a reversible change.

Re

When water is cooled, it changes an nges to ice. When ice is heated, itt changes to water.

What are some other examples of reversible changes that occur when re matter is heated and cooled? m 95

A Closer Look

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Liquid to Solid to Gas and Back Again n

Ice is water in a solid state. When ice is heated, ed, it w heated melts and becomes liquid water. If water iss heated, it also changes sta ate – it evaporates into a gas state called water vapor vapor.r.

Re ga

What hat happens happe when water ater vapor vap is cooled?

Go Online! line!

Visit the NGScience e ory to virtual laboratory arn how watch and learn er changes state matter state. ckCode: F6Y1 QuickCode:

96

n When water vapor cools, W it changes back into liquid water. This process is called condensation.

When the liquid water is cooled, it will freeze and change to solid ice.

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Irreversible Changes es

Re g

ion

Sometimes when matter tterr is g or cooling, changed by heating ged d back. ba it cannot be changed reversible. reversible e.

The change is irreversible.

Think Deeply

What are some e ible changes that tha irreversible occurr when you prep prepare and eat at your breakfast, lunch and dinner? dinne

98

When you fry a raw raw egg, egg, you use heat to change hange e the matter. matte er.

The egg can never neve ver be changed cha anged back to a raw egg. e

ed uc a

Cooking toast makes it hard and d crispy. Cooling the toast will not change it back to soft bread.

The change is irreversible. urning ning Popping popcorn and burning lso paper and wood are also irreversible changes.

AB

Go Online!

G Learn more about reversible and irreversible changes on the NGScience website.

QuickCode: J4R5

Activities 8.5 – 8.6

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Science Words

reversible change irreversible change

Re ga le du ca tio n

temperature melting freezing Review

1.

Describe two ways you can change matter.

quid chan 2. Which process occurs when a liquid changes to a solid? (a) Melting (b) Flowing (c) Freezing 3. Which process occurs when a ssolid changes to a liquid? (a) Pouring (b) Melting (c) Freezing 4. True or false. an chang (a) Matter can change state when it is heated. (b) Matterr can chan change state when it is cooled. changin to ice is a reversible change. (c) Waterr changing

1 00

Re ga le du ca

(a)

tio n

5. Label the changes as ‘reversible’ or ‘irreversible’.

(b))

c) (c)

(d)

1 01

A Closer Look

3D Printing Imagine being able to print an object just like ke e er. you can print words and pictures on paper. nd c ools Well, now you can! A 3D printer heats and cools g n. materials to build objects from a design.

Many 3D printers made of plastic. priinters build build d objects o The plastic heated asttic iss he heat eatted ed tto o become a liquid. The liquid plastic plas astic tic is is applied ap pp plie layer by layer to build the object.

Ass e each obje bjec ct.t. A ach layer cools, it becomes solid plastic la astic again. ag a gain.

1 02

3D printers rs are used to make many Th are used types off objects. The They ake body parts pa par and organs, to make acement ement parts pa for cars and pa replacement airplanes, rplanes, anes, ttoys to oys and even food.

Engin Eng rs often print models of their Engineers designs tto test them before making he real rea o the object. How is this useful?

1 03

t

What are some sources of heat?

How do people use heat?

n

9

Heat and Electricity

Re ga l

In this chapter ter you will ...

• list sources of heat at and des describe how they are used by people.

• describe how heat mov moves between objects. peo • listt the ways people use electricity. d cribe how electricity moves in a circuit.

• describe

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What are some ways people use electricity?

Go Online!

Access interactive content relating to this topic on the NGScience website. ngscience.com

1 05

What Is Heat?

Heat is a form of energy that makes things feel warm. When you place a glass on cold water in the Sun, it ga gains heat energy and feelss warm warmer.

du

a m glass g When you place a w warm of water in a refrigerator, gera or, itit loses heat ells cool l energy and feels cooler.

What happ happens to an object when it loses heat energy?

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Sources of Heat

What is the main source of heat on Earth?

ati on

A source of heat is something that produces heat.

On Earth, the Sun is our main and most important source of heat. The e heat from the Sun warms our whole planet and all of the living and non-living things on it.

Think hink Deeply Deep

What would tthe Earth be like if the Sun was further aw away? What if closer? it was cl

If there was no heat from the e Sun, Su n rt there would be no life on Earth.

1 07

ca t

What are some som other ces of heat? he sources

Think Deeply Touch your palms together and rub your hands back and forth.

Notice that your hands get warmer. What type of force produces the heat?

1 08

There are many any other othe sources of heat. Burning wood, wood gas and oil are sourcess of heat. W When these things hey produce prod burn, they heat.

Many appliances and devices in our homes are sources of heat too.

Ovens, kettles and toasters are sources of heat.

ga le

air Clothes dryers, irons and hair eat too. dryers are sources of heat How is heatt used use by people?

What is the e source of heat?

AB

Activity vity 9.1

1 09

Using Heat Engineer It! In small groups, design and build a solar hot water system. Use a thermometer to test your water heater. Compare the water temperature with other groups.

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People use heat heatt in in many ma different h t from fro the Sun keeps us ways. The heat We also also u s the heat from the warm. We use our clothes.

Sun to dry our olar wat A solar water heater uses the heat m the S from Sun to warm water for use nd the t house. around

We use heat in many ways in and nd d around our homes. In the colder er months of the year, we often use se e heaters to warm our homes.

ed uc a

We use heat in barbecues, ovens, and stove tops to cook our food. We heat water to boil food and make hot drinks.

We use heat to dry and iron our clothes.

err forr We use heat to warm water hing g dishes. disshes. shes he hes baths, showers and washing AB

Activity 9.2

111

Heat and Temperature tur Place a glass of water outside. Measure the temperature of the water four times throughout the day. Tell how the temperature of the water changed.

112

Temperature is a measure of how hot or cold something is. The more mor he higher its heat an object gains, the temperature.

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Try This!

We can get a rough gh indication ndication of y using sing our se temperature by sense ccurately ately measure me of touch. To accurately temperature, tem e, we can use a the meter.. A thermometer therm er thermometer. is a de e that at measures measu device temperature iin degrees Celsius Cels (oC) or degrees Fahrenheit hrenheit (oF).

du ca ti

Heat can travel through solids, liquidss and gases. Heat always flows from hot objects to cool objects. As the cool object absorbs the energy from the hot object, it becomes warmer. Heat continues to move in h this way until the temperature of both objects is the same.

Within an object, heat also moves from hot to cold.

Activities 9.3 – 9.5

Re ga

AB

Ex Explain what will happen to the he wax and thumb tacks attached to the metal rod. at

1 13

Think about the function of these appliances and the tasks they perform.

How were these tasks achieved in the past before electricity was discovered?

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Using Electricity Electricity is very useful to people. ple.

Many appliances in our homes es and an y to work. schools need electricity

ati on

Think Deeply

Light bulbs, ovens, refrigerators, efrigerators, washing machines es and nd kettles kettle all use electricity produced uced ed in power powe stations.

Batteries atteries Some ome devices, such as mobile phones, flashlights and many ny watches, get electricity from batteries. batte eries. es.

AB

Activity 9.6

ed u

Batteries i s come in different shapes sha apess i s ca an b be and sizes. Some batteries can thers used over and over again.. Others ce they hey no must be disposed of once icity. y. longer produce electricity.

Amazing Fact!

Some electric cars are powered by almost 10,000 small batteries.

They are able to travel hundreds of kilometers before the batteries need to be re-charged.

1 15

Saving Electricity Try This!

Make a poster about how you and your family can save electricity at home. Show your poster to your friends.

We waste electricity when it is used used by appliances that we are not ot using. us g.

Saving electricity helps to make make e ry e. It also electricity available to everyone. saves money. ple ways ways you can Here are some simple home and a at school: save electricity at home • Turn off lightss and curtains and a open o ng the the day. da blinds during • Turn off and heaters off appliances applian n you y are ar not using them. when

le

• Use light bulbs. s low-energy lowAB

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Activity 9.7

Electrical Safety Electricity can be dangerous if it is not handled correctly and safely. Always follow these electrical safety tips:

uc a

• Do not put too many plugs into one socket or power board.

• Do not put anything inside a socket ocket et other than a plug.

• Keep water away from electrical ectrical es. sockets and appliances.

• Do not play or run around und electrical cables.

AB

ga

• Always use an electricia electrician for any electrical repairs. epairs. rs Activity vity 9.8

1 17

Simple Circuits Go Online!

Build and test virtual electric circuits on the NGScience website.

QuickCode: M3W9

118

An electric circuit cu iss the t path along which electricity icity moves. mov In a circuit, ctricity travels tra ave from a source, the electricity h an ap pplia through appliance or device and back to source of electricity again. o the sou imple c A simple circuit consists of a battery, es and an appliance such as a light wires bulb. A switch can also be used to c ont the flow of electricity. control

ca

The appliance in a circ circuit cuit will only work when there is a complete path h along which the electricity can flow.

When a switch is in the ‘off’ position or there is a break in the circuit, cu uit, the the circuit is open and the appliance ance will wi not work.

Some materials, such as metal, allow electricity to pass through them easily. They are electrical conductors.

Other materials, such as plastic and wood, do not allow electricity to pass through them easily. They are electrical insulators.

ga

When a switch is in n the ‘on’ on’ position pos eak in the circuit, the and there is no break circuit is closed and appliance nd d the th he ap will w illl work. work.

Did You Know?

AB

Activities 9.9 – 9.10

1 19

Science Words

electricity battery electric circuit

Re ga le du ca tio n

heat temperature thermometer Review

1.

What is the main source of heat on Earth?

2. List two sources of heat.

3. List two ways you use heat at home.

e shown on each thermometer 4. What is the temperature in degrees Celsius? (a))

120

b) (b)

(c)

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5. List two appliances in your home that use electricity produced in power stations. ries.

6. List two devices in your home that use batteries.

7. True or false. (a) You should keep lights on even when them. en not using us (b) Using low-energy light bulbs can help save electricity.

8. List three things you can do to stay ay safe from fro electricity.

9. What is an electric circuit?

10. In which circuit will the light ght bulb turn tur on?

Tell how you know. (a))

(d) d)

R

(c))

(b) b)

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Re ga le du ca tio n © Blue Ring Media edia Pty Ltd td ACN 161 590 496 4 2013 - 2021.

This publication possible without the tireless effort of our production team. ation would not have been pos Special thanks to: Matthew hew Cole, Daniel Cole, W Wang Hui Guan Joseph Taylor-Pritchard, Sophie Taylor-Pritchard, Tejal Thakur eph Anderson, Halle T Taylor-Pr Varasinun Pookwanmuang, Saijit Lueangsrisuk arasinun Mathanattapat, Mathanattapat Kanungnit Kanu

Original Illustrations: Natchanuch Nakapat, graphicsRF, Blue Ring Media and Interact Images Illustrat Nat Royalty-free images: Shutterstock, Adobe Stock imag S