Cambridge Primary Science 4 Learner's Book PDF

 lntrod uction 3 Humqns ond onimols LI Skeletons 6 1,2.l.3 The humon skeleton B Why do we need o skeleton? r0 1.4.l,5 Skeletons o...

 lntrod uction 3 Humqns ond onimols LI Skeletons 6 1,2.l.3 The humon skeleton B Why do we need o skeleton? r0 1.4.l,5 Skeletons ond movement 12 os medicines.l.6 Drugs How medicines work 14 16 Check your progress IB 2 Living things ond environments 2,1 Amozing birds 20 2,2 A hobitot for snoils 22 2.3 Animols in locol hobitots 24 2.4 ldentificotion keys 26 2.5 ldentifying invertebrotes 28 2,6 How we offect the environment 30 2.7 Wonderful woter 32 2.8 Recycling con sove the Eorth! 34 Check your progress 36 3 Solids, liquids ond goses 3,.l Motter 3B 3,2 Motter is mode of porticles 40 3.3 How do solids, liquids ond goses behove? 42 3.4 Melting, freezing ond boiling 44 3.5 Melting in different solids 46 3,6 Melting ond boiling points 4B Check your progress 50 {il*:tl**?s  - -.MfIrt'Jsitrry\,."iMii Sound 4.1 Sound trovels through moteriols 52 4.2 Sound trovels through different moteriols 54 4.3 How sound trovels 56 4,4 Loud ond soft sounds 5B 4.5 Sound volume 60 4.6 Muffling sounds 62 4.7 High ond low sounds 64 4,8 Pitch on percussion instruments 66 4.9 Hoving fun with wind instruments 6B Check your progress 70 5 Electricity ond mognetism 5,.l Electricity flows in circuits 72 5.2 Components ond o simple circuit 74 5.3 Switches 76 5,4 Circuits with more components 7B 5.5 Circuits with buzzers BO 5,6 Moins electricity 82 5,7 Mognets in everydoy life B4 5.8 Mognetic poles B6 5,9 Strength of mognets BB 5..l0 Which metols ore mognetic? 90 Check your progress 92 Reference 94 Glossory ond index 9B Acknowledgements 104  skeleton frome Somettmes sheletons looh scorg. Sheletons bone skull ore not scoru. People, ond mony onimols, spine vertebro have o inslde their bodies. A skeleton is a hard, strong that supports our bodi.es Jrom the tnside. Hove you seen o skeleton before? There ore skeletons in some museums of onimols such os dinosours thot lived long ogo. Our skeletons ore mode of mony different bones, These bones ore different hord ond strong. sizes ond shopes. You con Jee[ the bones oJ your sheteton through your sh[n. -iil bgI ,.:'.,:..::,.*V fl Finding your bones Fee[ your head. How monu bones con Uou Jeel.? Hol.d gour hands on the sides oJ gour chest. Can you ftnd your ribs? How mony rlbs con gou Jeel.? Now Jee[ your boch. The bumps Uou can Jee[ ore the bones oJ your. These bones ore catled vertebrae. One bone [s cal[ed o Stand up ond put Uour honds on Uour hips. Can gou Jee[ your htp bones? Fee[ your hond bones. Why do gou thlnh there o.re so monu bones [n Uour hond? Did olt the bones in your hond Jee[ the some slze ond shape? What ore sheletons made oJ? Why must shetetons be hord ond strong? Why do you thinh the bones oJ your sheleton are dtJJerent shopes ond slzes? Bones ore not veru heovy. How do you Animol skeletons hqve bones thol ore different shopes ond sizes, thlnh this helps animals? Draw a plcture oJ what Uou think o person wlthout o sheleton might tooh t[he. : ::: Are oll skeletons mode of bones? Peopte and mony other onlmols hove a sheleton lnslde their bodies. Our sheletons support our bodies Jrom the lnsi.de. Our she[etons ore made oJ mony dtJJerent bones. Bones ore dilJerent sizes ond shopes. We have 206 bones in our she[etons. There are dtJJerent ki.nds oJ bones [n the sheteton' Long bones, lihe the bones [n our legs and orms. The bone is the long bone i.n your [eg. Short bones, lihe those in our frngers. Flot bones, [[ke those thot mohe up our shut[. ir'r':,,:,-ri;r.-ii' bOneS, lihe the bOneS [n Our Spi.ne. Mqking o skeleton Looh ot the humon skeleton on the opposi.te page. Notlce the sizes ond shopes oJ the bones and how they are arranged. Ptan how gou wi[[ mohe a sheleron Jrom d{ferent posto shapes. Arronge the pasta shapes on the poper to make Uour sheleton. When gou ore hoppU with Uour sheleton, glue the shapes onto the poper. r. Is the shu[[ made oJ one bone or monu bones? ,..r Why do gou thinh the shu[[ [s i.mportont? :tr Whtch is the biggest bone in the body? Whg do you thinh this is so? ; Which are the smollest bones i.n the bodg? ';. Whot ports oJ gour bodg do you thinh the ribs surround? Whg do you thinh the ribs are there? Women usualtg hove wider hlp bones than men. Why do you thlnh this is so?  eor bones jow bone collqr bone shoulder blode vertebro finger bones hip bone thigh bone knee cop shin bone A giroffe's neck con be up to 2m long. toe bone ::: li::i l.ril eitr:1.:a:i!J ;,: ll ;1', How mony neck bones :tdi.fl1ftiegl.lf:l ,#a:ji"l tt-i.,q:it,,r*.,i,.i li. ,:. -. ,l does o giroffe hove? ,' Our sheletons ore mode oJ Long bones, short bones, flot bones ond i.rregular bones.." The shu[[ ls mode oJ d$Jerent ftot bones joined together. ::rr.i:_1..::!i. :1r:j:ir::r:;:t.ii:+::r::a,i:::trJ.::; :: r:r:r:rt::,r::r: j::::.r: frocture X-roy invertebrote We grow ond get bigger because our sheleton grows. An odult's sheleton ts much bigger thon o chltd's sheleton. An adult's skeleton has stopped growlng. Comporing bone sizes Using a tope meosure, meosure the length oJ gour,. upper orm bone o thtgh bone o shi.n bone. Meosure the length oJ the cut-outs oJ the some bones on Uour teocher. Record Uour meosurements in o tab[e like thi.s one. Bome , Length in cm $Utre i;: Yescher il upper orm bone I thigh bone I --.._?------ _--..*_----- 1 i: shin bone !l i.i.*r.t'**i*:*s.r*.***rr"**t' Whose bones are longer? Predict what you thinh the length oJ o teenager's bones would be ond sag *hg. Sometimes we Jal.l. or hove occldents ond breok our bones. A brohen bone i,s colleda' ,'i ".,. Doctors tohe a speclal photo colled on ',, , to see f o bone i.s brohen or not. X-roys are photos thot let us see i.nside our bodles. Our sheleton supports our body. It mohes o strong Jrame This X-roy photo shows inside the body. We connot squosh our body eosi.ty o broken leg. Bones becouse oJ our sheleton. It gives our body shope ond don't stoy broken.The broken ends of the mahes it frm. Our sheleton olso protects our orgons. bone slowly grow bock together ogoin. :tfifilii:i:r:,ji'l:rIi':.:,+.:,1;:il...+.:i:,:l:.*l'i:r,l::fi.if;;.1;r.i;r*:i:jr1:;l:',.j,nir']i.. Not ol"[ anlmats hove a skeleton. Worms and jel.l.yftsh do not have o sheleton. An animol with no sheleton ls colled on ,:.:. 1:. ',': ,. :, ;'; ,:;. Jellyfishes do not hove o skeleton. l, i.,.-;lr.;,,r,'; fi. ;...'l,1t1;- I Whot would happen to o boby tJ its sheleton dld not grow? WhU do broken bones mend? i r,,r i il ,,1.,1:..1,,.,r ".i ,. '-.r,' I Why do froctures in old people toke much longer to heol We grow because our skeleton grows. thon froctures in children? The sheleton supports and protects the body. Anlmots without sheletons ore co[[ed invertebrotes.  muscles controct relox Bones are strong and hard. Theg connot bend but Uour body con move in monu waus. A[[ onimols with sheletons hove ;'::, 1..,.,::,]:,, ottoched to the bones. Muscles ore the ports oJ the body thot o[[ow : us to move i.n mang dtJJerent woUS. Musctes are Jound under the shin. Theg cover the sheleton ond give Uour body the shope that you hove. our bodies con move Musc[es olwoys work i.n poirs. One muscle controcts and in monv wovs' putls on the bone it i.s jolned to. This mohes the bone move. The opposlte muscte reloxes. How muscles work Muscles putl on bones to mohe them move. Muscles work by getttng shorter ond longer. When muscles get shorter, theg putl on the bones they ore joined to. We sag that muscles : ';,, , ,. The pul"l,lng movement otlows gou to move and do the actlon that you wont. When muscles :i ,,, they get longer and let you rest. I ,',; ,.,,' '' , : , ,'.. How muscles work Looh closely ot the muscles i.n gour orm and plctures opposite. Hol.d the wei.ght [n one hond ond stowly tiJt the we[ght up towords you. Put gour other hand over the Jront on Uour upper orm. ), Fee[ how the muscle chonges os you LtJt the weight. How does the muscle ot the boch oJ your orm Jeet? Straighten Uour orm. Fee[ whot hoppens to the muscle ot the boch oJ gour orm. Whot happens to the musc[e at the Jront oJ gour arm?..,.1:r::ii. -t:. tt How strong ore Uour orm muscles? Desi.gn o Jair test to ftnd out. -* Why i,s the heort not joi.ned to ong bones? The heort is o speciol muscle thot is not joined ony bones. +dj' iri :l.,.r." i * r#{j + lqn 'itl i:ii ,r.ri t"! rb 1! :t! ! How con we moke '-"'" muscles bigger? :.;, Musctes a[[ow us to move..."r Musctes are joined to bones..:,ii. ::,':: i.;.i:1"'.,. ll ::,.: :.i :l:..' r:. : :' il l::r:,.:,:'l'..., Muscles work bg putting on bones. ,,,, Muscles worh in poirs. 'l :'r''..: r'i'it:i :':ii  medicine prevent , \tt:F{-i:1] rstiili irrfl:riltrrr lgj u$trl rl,rr,fi6r:yil fi,p H.l{ rll:;i::ijX14.;r Drugs are substances thot mohe Uour body.as?r:::i.:.,i::.'i:-,i:"iF q"'is chonge in some wou. Many drugs hove good {ects but some drugs can horm Uour body. Tobocco is the drug in cigorettes. Tobocco con horm the lungs. When people ore unwell they toke ,',ii : We toke medlclnes to help make us Jee[ better when we hove on [t[ness. Some medicines olso ,,,, , us Jrom getting ttt. Not o[[ drugs ore medlcines. Tobacco, Jor exomple, is not o medlclne. How we toke medicines We tohe dilJerent hinds oJ medicines in dilJerent woUS..,:irl''.::ar,..{3*':.iar,.,rli ,-i:4{*'. 'lir Some medicines We breothe in We drink cough People who ore come os o powder thot we medicines from medicine to very ill in hospitol hove to mix inholers for help us to often get their with woter. osthmo ond other stop coughing. medicine directly breothing problems. into their blood through o drip. How do people toke medicines? P[on qnd corru out on lnvesti.gotlon to fnd out the dilJerent wqUS thot people you know tohe medi.cines. How wi[[ you collect the inJormotlon you need? How wi[[ you present Uour ftndings? ;ri, Why do we sou thot a[[ medlclnes are drugs, but not atl drugs are medlclnes? ;i Do you thinh we con use o creom os o medlci.ne Jor a sore throat? Say why or why not. :i Why do you think peop[e in hosp[to[ oJten get their medicine through a drip? ,i!"r,s, jr'.+ : {:,:,,e+, S..,.! ii; i;:' i,. i!:i.:j |i# Smohing is harmJul. Find out how I 41: :lr it - ,-. F :! j: i ?+: ,i.i. t :: E i.,ir r:.i Iii.,i i.:8" i :!: 4:!r ,irn rr ,4.+, E ++ + :rti 1- + smoking damages the body. How does on inholer help you to breothe better? L. ; - -, :l-..r.".,.. -..- ;-,r. ar*; i :8116.,. '-ii.-,-... :ri+ri(litisi;.: jr i.""S* $.,-.. Drugs ore substonces thot mohe Uour body chonge in some woy. Medlclnes ore drugs thot moke our bodi.es better when we are slck. Atl. mediclnes ore drugs, but not ott drugs are medlclnes. We can take medicines in dilJerent wags, such as powders mlxed with woter, by tnhoters ond directly into our blood. ffi  symptoms fever germs cure How do you hnow when you hove prescribe the Jtu? When we ore i[[, we have si.gns oJ the illness colled,,,i,, :. Dilferent lllnesses hove dljjerent sgmptoms. Looh at the picture below to see some oJ the sgmptoms oJ Jtu One oJ these symptoms is o Medici.nes help to tohe owou the symptoms oJ the lllness. OJten we become i[[ because FZvur Medicines con hetp to kitt the germs and mahe the iltness go fir e.Jne55 owqu. When medlclnes mahe on \ o h lltness go owau, we sou thcrt the zzz->= \4 medi,clnes us. 1- sore throal Body./, ach. These germs con Medicines make us better but we only be seen with o powerful hove to tohe them soJety. You should microscope. only tohe medicines iJ theg are glven They couse sore throots. to you bU o doctor, o nurse or on odult who looks aJter Uou. Sometlmes o doctor w[t[ medlcines. Toking medicines sofely Jimmy ond hls Jriends tolhed obout how to tohe medlcines soJelg. These are the[r ldeos. ,n It's okoy to toke someone else's medicine if they hove the some illness os you. H ,r You must olwoys toke the right omount of /-\ medicine.lf you toke too much it con be hormful. -\ ffi lf you forget to toke your medicine in the morning just toke more of lunchtime. ffi lf the instructions tell you io toke the medicine with food, you must moke sure ihot you do. ,,r.r,.*tir,' Dlscuss what Jimmg ond hi.s Jriends are saying obout how to toke medlclnes saJely and decid. r,J theg are rLght or not. You might need to ftnd out more lnJormation obout this. Mqhe an inJormatlon sheet about how to toke medi.cines soJe[y.. ','1. :: I :, :'i.::, t,..... ,t ', -rr ,1 Predict whot Uou thi.nk would hoppen ,J Uou didn't tohe a[[ the medicine the doctor prescrlbed Jor Uou. Why must some medicines be prescribed by Sgmptoms ore the si.gns oJ i[[ness. o doctor? Medlcines con cure ltlnesses ond moke them oo JJ owou. We must Jol,l,ow the lnstructlons to tohe mediclnes soJelg.  A F6r ',!&f A,F4B.&rf, a** q*/'\# , *.*1 ,*E *E*4 \#* -"#'k.t k't# * * E Hdr* 'h*d #-i!.#.*. ffi-ffi' Wri.te down the word that descrlbes eoch oJ the Jollowing' d,L*A Jrome mode oJ bone that supports our bodg. L:* A bone i,n the splne. ff: The bones oJ the heod. # Ani.mals with no sheteton. #e The ports oJ the body thot ottow our bones to move. ;Fi*5 I f;; Wri.te down the nome oJ one: {i ftot bone *+ long bone i# short bone # lrregulor bone. ffi#i Looh ot the drowing and onswer the guestions. L.E Write down the number oJ the muscle thot bends the orm. ;".- Exptoin how the muscle mahes the orm bend. Whot happens to the other muscle when the orm bends? I F€#rrt#::c ,r**# '**i**r*,*tr* Josle, Yasmln and Luiso meosured the length oJ their upper orm bones. These ore their results. Vqsmin Bone length in cm i-:1 Who do you thlnk i,s on odutt? i.-, Who do you thinh ls o teenager? i.: Who do gou thinh ts a child? ;.:i Exptoin Uour onswers to quest[sn5 i;:-,i...i'i How etse could gou show these resu[ts? i What opporatus do you need to meosure bone length? ri Explain how you can mahe thi.s o Jo[r test. {..:i Nome two reosons why we tohe mediclnes. 'l;: Which oJ these statements obout medlclnes ore true? A Al.l. mediclnes are drugs. B Medlcines give us sumptoms oJ lllnesses. C Never tohe medicines prescrlbed Jor someone e[se. D Medlclnes con hil,t hormJut germs ln the body. E Stop tohing prescrlbed medlcines when Uou stort to Jee[ better.  odopted hobitot These btrds llve ln veru dilJerent ploces. Iocol environment Shorp eyes for hunting. Powerful Some eogles con kill ond wrngs cqrry owoy smoll sheep. for liffing prey. Shorp bill for Eyes ore shorp cotching fish. Emperor penguins live of the underwoter for South Pole in temperotures os hunting fish. Thick feothers cold os -40 "C in winds of up to keep in to 100 km per hour. body heot. Webbed feet for swimming. Shorp eyes for hunting. The swift con fly ot up.l70 to km per hour. Smooth body shope for high speed. Shoped beok for cotching insects. WinEs tuck in for high speed. Eoch btrd's bodg is to help them survlve [n thei.r The hobltot is the thot they live in. What do you thtnh birds need Jrom thelr hobitot? 2 Bird wotching Mohe a plon Jor btrd watchlng near Uour school. Where w[[[ you do this? What witl you need? Wtl,t gou need to ottroct btrds? How witl gou do this? How much tlme i.s needed? Think obout how gou wi[[ mohe sure Uou do not frlghten the birds. Declde what records you need to mahe. Then spend some tlme observlng birds ond mohlng records. Try watchtng birds at dilJerent tlmes oJ doy. Is there a time when you observe more birds? How does the shape oJ o bird's beak help it to eot tts Jood? whu do blrds need good eyesight? why do some birds have webbed Jeet? How ore birds l::rll.i..,',1, ,."',, :,:r, : r :1r.:i _l: ::.: ,a , i,.: 'ii:i.: , : -:...t i.: -, r,, -,.r''i;..,, ;"," odopted to their hobitot? Birds ore adapted to he[p them [i.ve in thelr hobitats.  Con you see the snoil's she[l,? Can you see Its ege stalhs, mouth, and Joot? vorioble trend repeot 'G\ Snalls eat the leaves, stems, roots and "J Jruits oJ ptants. Theg hove no teeth. They have rough tongues which they use to eot leoves. They hove molst shin thot must not drg out. foot heod Theg [[ve under stones, rocks ond leaves. IJ the envlronment gets verg drg, snolls move bock into their she[[s. Snalls con chonge the wou theu behove iJ the envlronment changes. we observe snalls to see where theg like to [ive?.: :,:';:i :lr'ii.::'.,...t:l:::. disappeored Jrom thelr hobitat, what would happen to the birds eatlng snai.[s? 1:!;: l:' '':: :' :. ;r':. do snoils protect themselves when the envi.ronment [s too dry? is o bird that eots snolls sulted to the ploce in which i.t lives?  """"""" """"':. : Yorr rrrill need,: '.. : a tray leaves dry stones sand i i small sticks ,three snails ': :, Whot hobitot do snoils like? :............ Deslgn o choice tray like the one i.n the picture. P[an how gou w[t[ test some snolls to see where theg like to be. How wi[[ gou mahe the test Jair? Think obout eoch ',,]-.i.,:iit:-ti1-rir,:: 5uaL ot the cotour oJ the trou, the l.ight, the molsture and the surJoce oJ the trag. Do snoils lihe dry places or domp ptoces? Mohe a predlctlon. LoohJor ang pottern or i;r,;.'',::i in the resu[ts. i:ri*r]:-::=tq:lJ' the tests to get more useJul results. Present Uour results os o bor chort. Snail she[[s are oJten btoch or brown. How might thls cotouring be useJul to the snai[? Some blrds ore odopted to eot snolls. They have good eyeslght; theg con move quichty ond hove strong beoks. ""'::-. "r" ,.,, '-: How do snoils protect ,.t:r';, themselves from being eoten? , are suited in dtlJerent woys i :. Anlmols, such as snolls to the ploce theg [lve. IJ the envlronment chonges, onimols con sometlmes chonge the wou theu behove. 2 ::.::'1: :....-. Some onlmols eot plonts. Some animols eat other on[mo[s. Animots must [[ve in o hobitot woodlond i r,,j f,:r,r,,ri., :r! _r rf.r.i r rl i rii, rI ri r-r,l where they con frnd Jood. Here [s o hobitot. Rabb[ts, ducks and swans eot ptants. Foxes, howks ond owts eot other on[ma[s. ii # w Con you thinh three other onlmots thot onlg eot plants? "J Con gou th[nh ,J three other onlmols thot eot other anlmqls? 2 Observing locol onimols Wotk oround the school garden, tocol park, woodlond or meodow. How cou[d gou investigote which onimals live there? Whot science questlons would you ash obout the anlmols? Drow and wrlte notes obout the onlmols. Toth obout the onimals ond how they ore suited to the [oca[ environment. Con you descrlbe their hobitat? Do some onimals preJer one habltot? Do gou see o pottern ln gour results? rr: Nome three tocol hobitats. You mi.ght choose o. wet grossu oreo., or the borh oJ a tree. How ore onlmats odapted to llve [n these hobitots? Why do more birds visit o gorden thot hos lots of insects?. Some onimots eat p[onts. Some animots eot other onlmols. 2 i::r!"'lti;]ffi  There ore mi.tli.ons oJ onlmols in the wortd ond scientlsts have to be ob[e to identfy them. They need to sort onlmols into groups. Sclentlsts olso hove to be abte to identtJg an[ma[s. They do this with an ldentftcotion ,!l+:'i,'. There are heys Jor onimols ond hegs Jor plonts. Here [s on ldentfrcation keg. Each box has a questlon. BU onswerlng the questlons, we con identiJy a bi.rd, o cot, o frsh ond a snohe. Does the onimol hove legs?.t l,t., ',;,. '',tll,-,.:. -ti{&:. yes no Does it i Does it i hove 2 legs? I\,*-","--.-.""d. hove fins? i.1,.:;,... t:.,t 1:1_,,i '',:,. , '*ei r& yes no yes no -.8!}4si},.s*n:*!:BM5*!ue6 Does it hove Does tt r It is o fish. Does il slide feothers? hove 4 legs? on the ground? i ass!str*$k-*&:*!r*-.-*-*o!t yes y€s yes It is o bird. It is o cot. Itiso snoke. Moking o key Drow o heg which wi[L help you to identiJy a t[g er, shorh duch ond goot. ,i. does an identf,cation heg help us? How does Whot two onswers con be glven to o guestion Ln on identftcotion heg? How could Uou extend the hey opposlte to include o robbit? Find out the nomes oJ some groups oJ onimals. For exampte, whot is the nome oJ the group thot i.ncludes both humans ond cats? ::,..,:'.l' :r:::il, :1,' r1.,,,+ ;l+,,,;j,,,,} Choose Jour onimals. Drow a keg to help you ldentiJy your onimo[s. How would you moke ,i,l';rit i-:r'iri {,til.'.,i; iiuli1.,.. , , o key big enough for oll the onimols in , Sclentlsts need to be ab[e to your country? ". We con use an identftcotion hey to group animols.  Most lnvertebro.tes ore smo[[ ond hord to see. They hide omong grass, ptonts, leoves, stlchs ond i.n soi[. An ,,-,i:,:-,.r. i,s an lnvertebrate. Insects have si.x legs ond can oJten Jty. Ants, butterflies, greenflles and bees are lnsects. BeJore sclentlsts con mahe o hey, they hove to observe the onimols very coreJutty. An eorthworm is qn invertebrote but it is not on insect. i#tJffiqffi ffiffiffii ,ffidp:, ffiffitr* lffiL,,t#e r=&'F"ffi Bees ore insects thot produce honey. This butterfly hos six legs ond two wings. Ants work together in colonies. Whot ls an i.nsect? Is there more thon one wou to group onimals? Explaln your onswer. Do onlmots hnow whlch group they ore in? Exploin Uour onswer. Observi ng invertebrotes Co[[ect lnvertebrotes Jrom dfJerent ptoces oround Uour school. WhU should Uou spend the some tlme co[[ect[ng Jrom eoch p[oce? + Deci.de how gou wi.[[ record gour observotlons. +,..- '.a Invertebrotes ore verU smatt, so be careJut. Use o ,.,;,:.:r.i,::ii to help you. It wi[[ not horm them. CoreJul"l"y observe the lnvertebrotes' shape, cotour, number oJ legs, head, mouth, eoch i-.,:i'iri-::":,',r.:, sh€t[, shln, and how theg move. Disquss onu questlons you ho.ve obout them and how you could ftnd the onswers. Design on invertebrote hotel Design on lnvertebrote hotel that gou could buitd the schooI grounds. Sag whg i.n you thlnk the invertebrotes wi[l" lihe this hotel. Whot questions would -i'i+:ii you include on o tr,,:. :a:i-:. ,1 j:: _f, i!.ijt' ,tr; i:il;i r:,,i:t:.:r.:r. ,1 l:t'+, i.iil,,::r i1,;. ,i:L ii,."tlr I,,.-+.j!'l:j "+ir!..!i+: il{'i." ,,.:. key to identify a::."i+i?r -,r:i i;i ,:* r;;;l r:;tlli'!i; : Invertebrates hide omong gross, leoves, invertebrotes? plonts, stichs and in soi[. We can use ldentf.cotion kegs to group invertebrotes.  The Earth is home to more thon seven :,t.,r,., :-. t:. ,1..':,, :. :..-',:rti :i-'i'li bi[[lon peop[e. energy woste nqturol disoster It is also home to billions oJ animats mon-mode disoster.gf!l ond plants. protect q:fl itr'i{qNr+]:wrlla*itrrijt\5:En:wn.*.uttri+r,$v$\1!:H People, plants and onlmols nggd clgon olr ond. wotgr. Att oJ us need to use ,::,::; ,; ',,. We also moke o lot oJ ,'.,,,,,, People oJJect the Eorth in both good ond bod woUS. The picture shows some oJ the bod ways. Cw*oa An eorthquoke con kill onimols ond lf on oil tonker sinks, plonts.lt is on the oil spills into the exomple of o oceqn.This con kill thousonds of seo creotures ond seo birds.This is colled o We can o[[ help to the envlronment. 2 t.l,'.:1,',:; l:". How con we help the environment? Looh oround gour school ond the [oco[ Looh Jor things thot could damage the Looh ot lights, waste blns, heating, woter woste, olr conditioning ond toltet waste pipes. In your [oco[ &.*-.dY envlronment, con uou see [oco[Joctorles, Jorms, homes, roods, roilwoys or ships? Mohe drawings oJ these ond then [abe[ Uour drawlngs. Think about how these things hove con hqve a bad eJJect on the envlronment. How coutd gou reduce the bad elJects? , Rqilwoys con be good for the Mohe o llst oJ humon actlvlties , environment becouse they thot alJect the environment. con reduce the humber of vehicles Wrlte down some woUS in whtch gou :ir:' On the rOOdS. con Drotect IJ uour own envlronment. Whot [s o noturol dlsoster? I urve on exomple. How con we protect _ji. 'i lf the environment? People ojject the envlronment. People, other anlmols ond plonts o[[ need clean olr ond woter. Naturol dlsosters olJect the envlronment but ore not caused bg peopl.e. Most oJ the woter on Eorth i.s soltg. Th[s meons that we can't drink [t. Some people do not hove enough cleon Jresh woter to We need cleon Jresh woter to drlnk. We need [t Jor our onimals to drinh ond Jor our plonts. We do not olwogs look aJter our Jresh woter. Vi.tloges, towns ond cltieS ,..;:.-;, : t-:;I rlverS. People ond onimols moke woste which pollutes the river woter. The onimols ond plonts in the river die ond the woter is not sofe to drink. People who drink polluted woter, or eot lhe Rivers often begin in the fish from polluted woter, mountoins where the woter is con become sick or cleon ond sofe. Lots of onimols con die. ond plonts live in ond by the rivers. Bg stopping pollution we con mohe the land and woters clean ogoin. """"i i':. Tlorr. rrrill need,: '.. :'.. Your own river a large piece of paper pens pencils Mohe a large poster oJ the l.iJe oJ o river os i,t flows Jrom the mounto.ins, through Jorests, lahes ond post towns, Jorms ond Joctorles. Glve Uour river o nome. Dlscuss the ontmals ond plants thot might llve i,n the rtver ond how they might sulJer Jrom po[[ution. Wrlte on Uour poster to exptoln whot ts hoppenlng to the river. 2',, Cleqnlr-lg the uustea, Looh ot the pictures to see whot to do. You may wont to repeot this activltg. Why might this be o good [dea? Does the woter looh cleoner? Observe some fresh, cleon Stir in some cleon sond to Use o funnel ond filter top woter. pollute the woter. Observe poper to poss the woter how the woter hos chonged. through the filter poper. Con you see thot is it cloudy? Collect the woter. Whot causes river po[[uti.on? Whot can happen to the onimols and plonts i,n o polluted rlver? Whot con hoppen to people who drinh polluted woter? Whot do people drink where there is no cleon woter? Cleon, Jresh woter rs lmportont to humons, other onimals ond plonts. People oJten pollute Jresh woter. Polluted woter con horm people, anlmo[s ond p tonts.  Humons make o lot oJ woste. We throw owou clothes that could b€ ,,,.,:,,,: ,:. ,. A lot oJ woste [s buri.ed. This pollutes the soi.[ and thg ,..:'1.. 11i-,. 11.,'-;r,..:-t'. Some materlats can be ,:,;;;,,., r ,i.rr, SO thot theg dOn't have to be buri.ed. i,l,:,::l':ll,.lr,rt,..':llll,',:.,,'tl,:rrl i.lil lillillil:l:lii ,;;::r:::l:l:,:r::r;,i:::i:::::l;ii;:;ir;rrrtta rr:rlr:rr:l r:i II:III:.. ;IIIIII:I |:ii.:r:rrr.::::|:1 :!,air,':l-,tajl:iri..r:ri*.i.!1:::ii:i Glqss reeycling Poper recycling Plqslic recycling Generol wqste The woste gloss is The woste poper The woste plostic This type of woste used to moke new goes to moke goes to moke new is buried snd will gloss bottles. new poper. plostic things. pollute the soil ond ground woter. Gordeners ond Jormers recgcle plant materlol by mahing comPost heops. They pile up dead ptont moterial. ,,.;:,1 use the deod ptant materlol os Jood. This is whor we co[[ As the plont moteri.ol rots, [t turns into compost. Compost hetps ptonts to grow when it i.s odded to soi.[. 2 ,,, Moking o mini compost heop Gather some plont materiols. Put them ln a plastlc bag or jor. Add o littte woter. Ctose the bag or jar. Mlcro-organisms wil.l. begin to eat the plant materlol. Observe the changes over a number oJ doys. Record Uour observotlons. Plostic wosfe kills seo life Research the {ects oJ ptosti.c woste on sea 4\ rt> ffi creatures. Use books ond the lnternet. Write q _&_ fl\ report on whot gou fnd out. Exploi.n how the plastic gets i.nto the seo and how the plostic & ry6fro (_)4+_ horms seo creotures. Suggest whot could be done to help fn\ q, P:b lli ---n r \)-5 the situoti.on. Why should we mohe compost heops? Why [s it i.mportont to recyc[e materiols? How could you encouroge people to recycle more gloss ond l'. ,..: ,..1,, r ,',' - ;t'i+ " ,'1 ,'-1... ',:,.,.i.:':.' plostic bottles? When woste buried [t po[[utes the i.s soi.[ and groundwoter. Some materiols con be reused ond some con be recgc[ed. Plont moteriols con be recycled into compost.  ** '*.*ftn '4 i &z 4., f.@,,&i. s 'z@#l' ': ; ',@# 'r?*F \. ',. il a*n€ 4* : d*n""*-/\ddr#*+ =-,#'.#, ,\"#d = ,,.ii:.ri t..' Wrlte the nome oJ the hobitot shown in eoch plcture...: Soy why the onimol shown is suited to live i.n eoch hobi.tot. ffi Looh ot this onlmol ond the Jeotures oJ its bodg. Wri.te down how Uou think its bodg ls suited to its habltot. toil mouth/ teeth feet/clows ffi -!: :11r:i::l ffi Construct o hey to ldentfg these pets. ,:l:it:;:.r'iilr g,,._; Eoch dou, Tabansi the Jormer dumps monure Jrom his qnimols on the lond next to the rlver. The bar chart shows how monu tonnes he dumps each doy in one weeh. 2A.t, __ 15 P C o.= t0 IJ c Otr Sundoy Mondoy Fridoy Soturdoy On which dag wos there least pollution? On whi.ch dags wos there most pollution? How woutd this pollution olJect the river? 2  motter solid phose 90s liquid irL,,urf,*nilt:r.!rrq,*iprar Hifr ,,r-|r.r',N'r rturrr_1l! id f"ijrf,:r 1rll.till::ri [s evergthlng oround us..: ia.'.,3 &i i, ;t ',. \' i;l | ( i.) nr:' ,/' ] t/ ' i:r A brick is o solid. Woter is o liquid. The oir inside the bubble is o gos. Motter exlsts [n three dfJerent stotes. A stote oJ motter [s colled o. These phoses ore hnown os , or It is Sun['s tenth btrthdoy portu. Identfy two solids, two goses ond one liquid on his blrthday tob[e. Goses in oir Air everywhere oround us. Ai.r is a mlxture oJ dfferent i.s gqses. We can't see or sme[[ the goses in o[r. A gos colled nltrogen mahes *p oJ the oir. + Ai.r olso contalns o gqs called oxggen. We need oxygen to We breathe ln oxggen. We breothe out o gos called [i.ve. co.rbon dioxlde, which is olso Jound in olr. 3 Some goses do hove o cotour. Some gases atso have o sme[[. Hydrogen suflrde smells [i.he rotten eggs. Chlorine gos irifii;iill is yellow. L culftde i Mqking corbon dioxide Put some blcorbonote oJ sodo [n a surgicol or rubber gtove. Then, frl"t the glass bott[e hal,Jwog wlth vinegor. Attoch the gtove coreJully to the bottle uslng on etastlc bond. Ensure thot you do not mix the bi.carbonate oJ sodo and the vlnegar whilst ottochlng the glove. Once ottached, shahe the bi.corbonote oJ sodo into the vinegor. Observe whot hoppens. The gos gou hove mode Ls corbon di.oxtde. ::, What stote oJ motter is: vlnegor bicarbonote oJ soda produced in the reactlon? r Draw o plcture to show what hoppened when the vinegor ond blcorbonote oJ soda mlxed together. LobeI the liquid and the gos. How do you decide if something is o solid, o liquid or o gos? Matter ls everythi.ng around us. Motter can exist in three dilJerent phoses, sotld, tiguid or gos. Ai.r ls a mlxture oJ dilJerent goses. 3  oJ somethtng. porticle scientific model.r:rrir:r!ar:iiL:4q!r!t{i}\Irtiir:,{tD,r.etqlt.r!!!!r Scientists con use o ,, to explaln how ond whg something hoppens. The portlcle model is a good woy to exploln the dilJerences between so[i.ds, li.gutds and go.ses. This model soys that a[[ motter [s mode up oJ porticles. In reol [fe, the portlcles ln mo.tter ore too smo[[ to see. In the model we con show the portlctes os litt[e botls. The partlcles tn motter ore a[wogs movin!, even in things thot looh stt[[. The omount oJ movement oJ the parrlcles decldes whether something i.s o soltd, l.iquid or gos. Porticles withih o solid ore Porticles within o liquid ore Porticles within o gos ore pocked together very tightly close together but they con spoced for oport.This is why in fixed positions.This rnokes slide post eoch other ond goses con hove ony shope. ii difficult for the solidito chonge ploces. Becquse They con olso be squoshed chohge shope. of this,liquids con chonge eosily. shope eosily. The porticle g0me Divide lnto groups. Imogi.ne that eoch Person rn uour group [s a portlcte tn o solid, o liguid or o gos. Look ot the plctures to see what to do. a *i * _-sr N,, #s&" solid liquid rx- 90s Try to shohe Jrom slde to si.de. Whot do you notice? Trg to move closer together or Jurther oport. What do gou notice? Trg to chonge the shope oJ your group. What do you notice? Now chonge group and repeot the activity. Compore what hoppened when gou trled to sho.he as so[[ds, liqulds ond gases. Whot happened when you tried to move ctoser together i.n eoch case? What happened when you tried to chonge the shope oJ each oJ gour groups? How does the porticle gome demonstrote the porticle model of A[[ motter i,s mode up oJ particles. motter? Soltds heep thei.r shope as the portlctes do not chonge pos[tion. Ltguids con change thei.r shope os rhe porticles ore ab[e to s[i.de post each other. Goses can hove any shope os the porti.cles move Jar awag Jrom eoch other. Gases tahe on the shope oJ their contalner. i.::.ntt:lt l.i.r,:.!:a.::t:;..4::::.:i:.: :i: :: pour Solids Try to squeeze Uour desh, choir or penci.t. Con gou moke it o d{ferent shope? Most soli.ds con't be squoshed into o dilferent shope. Remember the particte modeL. Porti,cles wlthi.n a so[[d are poched closel"gtogether. There is no spoce Jor the partictes to tohe on o dilJerent shape. Liq u ids Ameeno,lcon moke woter chonge No you con't, Predict whot witl hoppen its shope. ,",nrr,ii Soreeno. ,'i {l iti lf " when lOU '.,..:,,, SOffte Wotef ,Ji' r'',',r 1 "" r rt'u: onto a flot surJoce. Prove thot woter con chonge its shope P[an a demonstratlon to prove thot water con chonge its shope when you pour lt. Decide on the equi.pment Uou wi.[[ use ond whot gou w[tl" do. Now corry out the demonstrotlon. Use the parti.cle model to explain why liqulds con chonge their shape. 3 Goses IJ gases ore contoined [n something they take on the shope oJ the contolner. Look ot the plcture. Here the gas [s contalned insi.de the i],:':,,::,... When there is no contalner goses spreod out. Observing how goses behove Dip the rlng into the soapg woter. Btow oir through the ring to mahe bubbles. Whot is the gos inside the bubbles? Whot happens to the gos when the bubbte bursts? - !.rr::r r i -j. !1r iii - ,;,r:: f'ilt'i: ;: i :lj,*,:.i:rr.€.;.,:!1,:il.::,r i, ::,.. Draw o plcture oJ portictes oJ oir inside o bubbte. Gos is sometimes used :,-,' Draw the some number oJ particles oJ oir when os o Juel" Jor coohing. the bubb[e bursts. Why do we heep this ,; Whg con't you change the shape oJ a brick by gos ln seoled metot sgueezlng tt? contolners? Drow a labelted diagrom to explain how a puddte Jorms when it rains. How do you think it is possible to squeeze some solids into Most sollds do not change shope. nt shopes?., Liqutds tohe the shope oJ the contqiner theg are [n or spreod out over a surJoce. Goses only have a shope when they ore contained withln somethi.ng.  Sobero's ice-creom melting freezing storted os o Jrozen sotid. steom boil When the sun heoted the lce-creom it chonged ','&,S','& r,. :::!&,,.rs8:,.*x6:,:.&a.. to o Liguid. This chonge x:;rqq q i- $ "x r, Jrom so[[d to liquid is callgd ,.::i:: ].: , ::'i. We can show melting in thi.s wo!: sol"id heot couses mettlnq , ltqutd the opposite oJ meltlng. Freeztng [s i.s Woter exists in three different phoses: ice (solid), woter (liquid) when somethlng chonges Jrom a liguid to o solid. ond woter vopour (gos),which we often gqll.r'1 ,'.1.', 1' ,. Whot hoppens to ice when it is heoted? Put the lce cubes into the pot. Heot the pot on the hot plote..-, Predlct whot gou thi.nh wi[[ hoppen to Be coreJul. oJ the hot I e the ice. p[ote, [t can burn Uou. Whot does hoppen to the ice? Steom con olso burn gou. ThLs i,s the phase chonge the ice goes through when gou heot [t, heot solid phose (ice) Liqutd phose (woter) Now heot the woter unt[[ i.t storts to Observe how the woter changes. Whot hoppens to steom when it is cooled? Your teocher witt hol.d the shlny board i.n the steam. Predlct whot you thinh.-. witt happen to the steom. I Be careJul. oJ the steom, Observe whot hoppens. a it con burn Uou. Put the l"iguid gou coltect ln th,e Jreezer Jor 30 min. Predi.ct whot witt hoppen to it. :.* CopU and comptete the sentence below. Fil.t in the phase changes the woter went through when it cooled down. steom ( _ phose) cooI down ( phose).rrtt What hoppens to the woter when Uou put it in the Jreezer? CopU and complete the sentence below. Fil.t i.n the phase changes the woter went through when tt Jroze. cool down woter ( phose) phose). How does the porticle :: :.:.. 1]:]r. l:}!]]: model help us to iilil: +i: + r:. 4 ! a: rr r:'; : understond melting heated and [t ond freezing? changes lnto o l.iguid. heoted and lt changes lnto o gos. Freeztng occurs when o llguid is coo[ed ond lt changes into o sotid.  Compqre melting in different solids Ploce an tce cube in o pon. Do the some with the chocolate and the butter. Predlct which substance Uou thinh wi[[ melt ftrst when Uou heot [t. Stort heotlng eoch substance ot the some Be coreJul. oJ the hot time. Record the tlme you start. I a plote, i.t con burn Uou. Observe careJullg. Record the time token Jor each substance to completelg mett. melting ice melting melti chocolote melting butter Record Uour results in o bor chart. Descrlbe the phose change tho.t each substonce went through when you heoted it. How did gou try to moke thi.s investigation a Jo[r test? In what wogs wos the investlgatlon not o Ja[r test? Whot wtlt happen to the woter iJ gou contlnue heoting it? Even metols lihe ond iron wi[[ melt rJ theg get hot enough. Metols hqve to be heated i.n a Jurnoce to me[t. When the melted meto[ cools it becomes o solld ogoi.n. This gold wos heoted until it The gold cools in the mould ond melted,Then it wos poured becomes o solid ogoin.These solid into moulds. gold bors ore colled ingots. Here ore the phose chonges the go[d hos passed through, heot cooI solid l"iquid so lid Why do you think different substonces toke different times Some so[i,ds toke longer to mett thon others. to melt? Even metols mett f theg get hot enough. Every substonce melts and boi.[s. Dilferent substonces toke d{ferent tlmes melting point boiling point ltrltiirll",rar!tsii!S::u4+I1il:'i1-rij,-Psqlqriflllll+lllr]sr*ra]*ri:jrrr:l}taHn,s:jI to melt becouse [t takes dtlJerent omounts 1l 'Celsius oJ heot to melt them. The omount oJ heat ! in o substonce is cotled the tempero.ture. 5C The temperoture ot whlch a substonce 3() mglts [S [tS.':ri::-ri,1''::,,; i..:.:-.,,,',r. Thi.S iS whgn i.t 20 changes Jrom o sotld to a tiguid. t0 The temperoture ot which o substonce to i IU bO[tS [S itS :'ii :'., ,. ] ,',.',.,,,.:: :,. This is when lt ]A chonges Jrom o liqutd to o gos. 4O 5O We meosure temperoture with o This is woter boiling. thermometer.The unit we use is Woter hqs o boiling point of.l00'C. degrees centigrode,'C. Meosuring the temperoture of woter Put some woter ln o cup. Meosure the temperoture oJ the water with the thermometer. Record the temperoture ln "C. This is the temperoture oJ the woter of room temperoture. Put the lce cubes in o pon and heot them. As soon os the lce cubes hqve melted, remove the pon Jrom the hot plote. Tohe the temperoture oJ the woter. Record the temperoture. Th[s the melting point. i,s Now heot the woter until i.t boils. Toke the temperature oJ the steam. Record the temperoture. This [s the boiling point. I \ Be careJut oJ the steom, l.3-1 Safety l it con burn Uou. '::-. t' -::_.: : r.. 1r -..i. ,:.r'...1 ':i, What temperotures dld gou record Jor, '., the melti.ng point oJ woter '.: the boiling point oJ woter woter of room temperoture? Draw a bor chort to show these three temperotures. The meltlng point oJ woter [s 0oC ond the boiling poinr ts 100"C. Did gou measure these temperotures? IJ not, why do you thlnk the temperotures you meosured were dfJerent? Why shoutd Uou never put Uour hand ln steom? ff-ia - :'' r:r,:.:., ,..'!,.:, How does the porticle model help to exploin o melting point? The botling polnt the temperoture ot whlch Ls o substonce chonges Jrom o liquid to o gos. The melti,ng point is the temperoture at whlch o substonce chonges Jrom o so[[d to o tiguid. 3  A {'4 4\ A- a.e \. jA C A G&. 4q fa *} \*# * -'\5 \*, -\- \l\l * ; - '4 J = \*/i-,,-.4'nif #}=,,L rt$ffi ffi Whtch oJ the Jollowing substonces are sotlds? Which ore li.gui.ds and whlch are goses? oil plostic poper corbon dioxide oxugen vlnegar ir."# Which oJ these stotements describes o sotid, o ttquid or a gos? '* Tokes on the shope oJ the container. t Spreads out in o[[ directlons. # Does not change shope eosi.ty. # Is oJten colourless. i:s Connot be squashed..-- t:'utr il :! - ntt v::4 :; Whot ore the three phases oJ woter? n*" What i.s the boiling point oJ woter? !P Whot i.s the melting point oJ ice? Does the diogrom betow represent a model oJ a solid, o liquid or o gas? i+, :!'i Write a sentence to exploin Uour onswer. @ @ @ @ @ @ @ @ @ @ @ @ @ Amu[ ond J[oo wont to compore how long it tokes to melt margorine ond butter. Theg wont to ptan o Joir test..',, Whtch oJ these actlons shoutd they tohe? You con choose more thon one. A Put equal amounts oJ butter and morgorine together i.n o pon. B Put equol amounts oJ butter ond morgarlne i.n a pan ond a pot. C Put equol amounts oJ butter ond margarlne [n two ldenticol pons. D Heat both pons one aJter the other on the some stove. E Heat eoch pon on an ldentlcol stove storting ot the same tlme. F Heat one pon on o gas ring and the other pon on an electr[c ptote starting at the some tlme. i,, Drow dlograms to descri.be how the butter chonges Jrom a solid to a l.iquid. Use the porticle mode[ [n your di.ograms.  i; :.4 i I, source overheod. The oeroplone is o , oJ sound. Sunltq hears the sound when [t enters her ears. The sound can : ,, Jrom the oeroplone to Sunlto's eors. Moke o tin con telephone Looh ot the pictures to see whot to Use the string to join Give one tin con to o portner. Keep the the two tin cons. other one yourself. Wolk owoy from your portner until the string is tight. 4  3I.ur rG, Tolk':softli inlo,your +i6,,66,6; Your portner should listen ihto''fheir,ti6,6q6, :Pid, your portner heor your voice? This is how the tin con telephone works. Sound trovels through materlals, tihe stri.ng. Sound can trovel through dilferent hinds oJ materiats. ,'. s ffi'E.€#,$#€xe*e"egg ;E Whot [s the source oJ sound in the tln con telephone? :e Which moterlals does the sound travel through in the tln can telephone? iS Why did the Natlve Amerlcon people lie with one eor in the ground to listen Jor enemles or onlmals to hunt? r s i. s,i{ &d f.s*.{ E,ts**T"***.+.*. *Xl _* E.S Hge5.g=* H+regg"ry'pg* ; Sounds come Jrom sources. ; Sound trovels Jrom o source to our eors. ; Sounds trovets through materiols lihe string. 4 i:it.ru**i  T7orl rrrill need,: a source of sound, like a ticking clock a balloon filled with water a block of wood or a wooden door Cover one eqr. Con you heor the clock ticking? Sound trovels better woter through some moterlals thon through others. Looh ot the plctures to see whot to do. Remember to stond the some dlstonce owau Jrom the cloch eqch time. Cover one eor with your hond ond one eor with o bolloon filled with woter. Con you heor lhe clock ticking? Llsten careJully. How wett dtd gou heor the sound each time? Draw q table like the one shown. In the tob[e record how we[[ you heord the sound through the d{ferent moterlols. Cover one eqr with your hond ond put the other eor ogoinst o blockiof wood. Con you heqr the ,& il4 f, Show how loud the sound was bg uslng tichs: ,r/ : soJt / / -louder ,/ / / -loudest.1 Loudrness of sCIuxmd : I *'-35 i "--i :l : Which moterlol did you heor the sound best through? How did you moke the lnvestlgatlon a Jair test? Wholes communicote with eoch other under woter. The sounds trovel o very long woy, Descrlbe how you could investtgote whether sound trovels best through wood, plasti.c or metot. Why do you think sound ii,-i.i..rr -1+'.j1.;r.,,i.!,.t i;l;.i l; + trovels best through solids? throug h dilJerent moterlols. '. Sound travets through solids, liquids ond goses. Sound trove[s best though solids. 4 Sound trove[s through dfJerent moterlals. But how does sound travel? Jumping rice Put the plastic wrop over the top oJ the jor. Keep the wrap in place with on elastlc bond. Sprinhle o Jew rice gralns over the wrop. H[t the slde oJ the jor wlth the pencil. Whot happens to the rice? Hol.d the tln trag close to the jar ond bong it wlth o spoon. What happens to the rice? Predi.ctwhot wil.l. happen f gou clop Uour hands next to the jor. Try it out. Wos Uour predi.cti.on correct? Sounds are mode when things A ,,,..,..,:',,. [s o veru quick movement boch ond Jorth. You oJten connot see vlbrations, but you can Jee[ them. Hotd Uour hand in the mtddl.e oJ your throat ond hum o tune. You wlttJeet the vlbratlons ond heor the sound. You con see these guitor strings vibrote. {, :;'-."., ','. Sound trovels becouse vibrotions trovel Why did the rice grolns in Activity 4.3 move? You see the rice groi The tin troy vibrotes when you hit it. The plostic wrop \ vibrotes.The rice groins vibrote \ ond move. \ /r,.*.* \-\ "%ii t,, The vibrstions trovel The jor vibrqtes through the jor to the when you hit it. plostic wrop. The oir sround the tin troy vibrotes. {.$+;e,**al"i*:1.1+-l:sE*l+.,s$ j,E Did gou hear o sound when you hit the jar? why?.*:?: Thinh bock to the tln con telephone. Whlch moteriots vibrated when gou used the tetephone?.r:.. -1 ,, :.a.l:.. j How could you stop the 'E&F-Eg*a:Bx '&g-*r i. ;- i;,..1 :, =-, f--#,F,rtgg*g'H* ,,soUhd trovelling in o tin con telephone? :.;, Vlbroti.ng objects make sounds. ,.;. Vlbratlons move Jrom the vibroting object through moter[a[s. We heor sounds when the vlbrotions reoch our eors. Sound trave[s becouse v[brotions trove[. 4 I;+lir:rj  Looh at the plcture. Do you thlnh the sound ls 'i.'.ii:': or'....:,? What mohes the sound [ouder? A motorbike storting up is o loud sound. A whisper is o soff sound. Listening to sound through o tube Looh at the plctures. CopU Hold the clock next chlldren in the pictures ore to my eor so thot I Con you heor the i con listen to the tick.rdt clock now? ls it louder ilSl tYf' or soffer thon before? ""*..i'.r:,,qq,:riol,i1r*.,rrH, \,  Wos the sound oJ the clock [ouder or soJter when Uou moved the ctoch Jurther Jrom gour eor? WhU do you think thot this hoppened? Use the words vlbratlons, trave[ and olr in gour onswer. Wos the sound [ouder through the tube? Why do you think thot this hoppened? Plonning o fqir test for loud ond soft sounds Thinh oJ o questlon obout loud ond soJt sounds. P[on o Joir test to frnd the answer to Uour guestlon uslng everydoy moterlols. In your pton, list the materlals Uou would use ond the steps Uou woutd tohe. Exptaln how Uou woutd mahe it a Joir test. Suggest how Uou woutd present gour resutts. This is, the, oldest type '.. Looh at the plcture. of music ployer with no electronic ports. How do you think the muslc wos mode [ouder? How do people in your community deol with Sounds can be toud or soJt. loud sounds? Tropping the sound vibrations mahes the sound louder. 4  A sound is louder when the vibrotions are :i:,.:.: :, : :,':.t.:: r.:::li: : :"i;i I _:.._r.,:. bigger. The ,,. oJ a sound is how loud volume decibel sound Ievel meter or soJt it is. ':rriulw!s,r?i:q[f f $r{r}*l inrlwjr\rr\i! ra'{r]r.i,i, ir-r s A ,..,,:.r..i,r', (dB) iS the unit we use to meosure the votume oJ sound. (( (( \ These are the votumes oJ some evergday sounds. Very loud sounds (louder thon 85 dB) con damoge our eors. tr.e..@p 60 70 100 10 12A 224 R,@ 1 tu\t\\ ) ffi & ;t :rr1r1:lxi":i;ii i:lia1iiirj1., ',.:.;l:1:i.':l i.,iili.Ltt,lii Some people play loud muslc. How can gou frnd out how loud the muslc is? You can use o A sound level meter. 4 ,','' ",,', '''' Meosuring sounds Thinh oJ some sounds to meosure, Jor exomple, clopping honds, btowing o wh[st[e, slomrnlng a door or the closs tothing. Predict which sound wi[[ be loudest and whlch wltl be soJtest. P[on how you wl[[ measure the sounds. How wi[[ you moke sure that rhe test ls Jotr? P[an how you wi[[ record the sounds. Witt gou use o table or a bar chort?.ili.l1-;::;: ,r!li::l..'. Predict the volume oJ sllence in declbets. ir. How con you frnd out f your predlcti.on is true? ;r :i-ii:.i: :.:'1";.'.;,,.:.1r.',::.i'1::.:;i+ :,:]j. 1. :. Which sound was l,oudest? ,r Which sound was soJtest? ,:i Were Uour predictlons correct? i,,i. Exploin whg some sounds are loud ond other sounds ore soJt. t:l :: ,"ir:l l,il ,rrir.;r:r :'1:.i.i" r :1,.i; How does o sound level meter meosure volume? ,. Sma[[ vibroti,ons couse soJt sounds.. Large vibrotions couse [oud sounds.. The votume oJ o sound i,s how loud or soJt the sound is.. We meosure sound [n units coll,ed decibels.. We con use o sound [eve[ meter to meosure the votume of sounds.  There ore some sounds thot we don't [[he or sounds that ore too [oud. We con muffle eor defenders silencers sounds thot we don't wont to heor. This meons thot we mohe the sounds guieter and less clear. Loud sounds con hurt our eors. Some peop[e worh [n veru nolsy ploces. They need to protect thei.r eors. Theg weor to mulfte sound. The sound of this jock hommer is very loud. The volume of sound from on electric hond drill could The sound inside on domoge eors. oeroplone con be very loud. We frt ,' to cors, truchs ond motor cyctes to mulfle the sounds oJ their engines. In butldings we use corpets ond curtalns to stop noise. Sometimes the spoces between wa[[s are frlled wlth materiols that don't let noise through. This motorbike silencer muffles the sounds of the engine. 4  i: Yorr. rrrill need,: different materials a source of sound a shoel.. Findir:g mu? !r.:i:l s'mmterEm :lr'rriir fr