ESSAY QUESTIONS-Ibank.doc

8/11/2019 ESSAY QUESTIONS-Ibank.doc

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Science SPM Paper 2 (Essay question) 1

SCIENCE SPMSCIENCE SPM

NAME :

CLASS :

ONTENT

FORM 4CHAPTER 1 SCIENTIFIC INVESTIGATIONCHAPTER 2 BODY COORDINATIONCHAPTER 3 HEREDITY AND VARIATIONCHAPTER 4 MATTER AND SUBSTANCESCHAPTER 5 ENERGY AND CHEMICAL CHANGESCHAPTER 6 NUCLEAR ENERGYCHAPTER 7 LIGHT, COLOUR AND SIGHTCHAPTER 8 CHEMICALS IN INDUSTRY

FORM 5CHAPTER 1 MICROORGANISMS & THEIR EFFECTS

ON LIVING THINGSCHAPTER 2 NUTRITIONCHAPTER 3 PRESERVATION & CONSERVATION OF

THE ENVIRONMENTCHAPTER 4 CARBON COMPOUNDCHAPTER 5 MOTIONCHAPTER 6 FOOD TECHNOLOGY AND PRODUCTIONCHAPTER 7 SYNTHETIC MATERIALS IN INDUSTRYCHAPTER 8 ELECTRONICS & INFORMATION

& COMMUNICATION TECHNOLOGY ICT!YL KONG @SMKSARA OK2!!"


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YL KONG @SMKSARA OK2!!"


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ESSAY QUESTIONSCHAPTER 1 : SCIENTIFIC INVESTIGATION

1 The length of a spring is affected by the weight of the load

(a) Based on the statement above, write one suitable hypothesis.

1mark !

(b) "sing a spring, few loads and other apparatus, describe an e#periment to test your hypothesis in(a) based on the following criteria$

%im of the e#periment 1 mark ! &dentification of variables 2 marks ! 'ist of apparatus and materials 1 mark ! rocedure 3 marks ! Tabulation of data 1 mark ! onclusion 1 mark !

ANSWER

(a) *ypothesis+ The heavier the weight of the load, the longer the length of the spring.(b) %im + To study the relationship between the length of a spring and the weight of the load.

ariables that are+(i) manipulated+ the weight of the load(ii) responding+ length of the spring(iii) constant+ the same spring - diameter of the spring.%pparatus+ spring, five different weight loads, retort stand, ruler

rocedure+1. The spring is hung on a retort stand.2. The length of a spring is measured.

3. % .2 / load is hung to the end of the spring and the length is measured.0. tep 3 is repeated by increasing the load .2/ each time until 1. /.. The results are recorded in the table below

Tabulation of data

eight of the load, -/ 'ength of spring, l - cm

.2

.0

.4

.51.

onclusion

The length of the spring increases as the weight of the load increases. *ypothesis is acceptable.



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2 (a) tate the importance of a scientific investigation method in ac6uiring scientific7nowledge.

0marks !

(b) 8ainal wants to carry out a scientific investigation to measure the response time of hisfriend. 9#plain the steps he has thought ahead before he can start the e#periment.

:our answer should include the following$

&dentify the problem 1 mark ! ;perational definition of response time and other variables. 2 marks ! 'ist of apparatus 1 mark ! teps in the method used 2 marks !

ANSWER

(a) &t is a systematic and complete way to ac6uire scientific 7nowledge &t enables students to learn the right way of ac6uiring scientific 7nowledge &t inculcates the right values and attitudes in students &t helps to minimise misconception or pres thumb and secondfinger at the ?ero position.

2. The meter rule is suddenly dropped and the friend is re6uired to catch the rule with the thumband second finger.



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Science SPM Paper 2 (Essay question)

3 (a) tate the items in a correct se6uence when writing out a report.0marks !

(b)

tudy the information above and construct the concept of scientific investigation.:our answer should be based on the following steps+ &dentify the common characteristics @evelop the initial concept in the scientific investigation method Aive two other e#amples to the concept 9#plain the actual concept

4marks !%/ 9

(a) %im, roblem statement, *ypothesis, ariables, %pparatus and materials, rocedure, esult,

@iscussion, onclusion.(b)ommon characteristic+ cientific attitudes and noble values are practised in scientific investigation.

&nitial concept+ cientific attitudes and noble values should be absorbed during learning and teachingscience.Two other e#amples+ ystematic - ational thin7ing - Cair and impartial - *ardwor7ing and perservering.%ctual concept+ ractising scientific attitudes and noble values will lead to a better understanding andinterpretation of a scientific investigation.



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CHAPTER 2 : BODY COORDINATION

0 The figure below shows two patterns of bloc7 arrangement.

tudy the following statement.

% man who has seen the arrangement of wooden bloc7s as shown in the figure above can rearrangeit blindDfolded.

(a) uggest a hypothesis to investigate the above statement.1mark !

"sing si# identical wooden bloc7s of similar si?e, describe an e#periment to test your hypothesisin (a) based on the following criteria$ %im of the e#periment &dentification of apparatus rocedure Tabulation of data onclusion

Emarks !ANSWER

(a) Finaesthesia allows a man to estimate the position of ob


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Science SPM Paper 2 (Essay question) H

(a) tate the differences between voluntary action and involuntary action.0marks !

(b) % patient is not able to wal7, hold things or wa7e up by himself, but he is still able to tal7 andremember his siblings after an accident.9#plain what has gone wrong with his brain.:our e#planation should include the following+ art of the brain which is in


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4 (a) @escribe how the sideDeffects of e#cessive alcohol consumption affect the driving s7ill of ahuman.

0marks !

(b) The figure below shows several effects on human health of the habit of e#cesive consumption of alcohol.

tudy the above effects. @escribe how e#cessive consumption of alcohol may cause theabove effects on human health.:our answer should be based on the following+ &dentify the information &dentify the common characteristics elate the common characteristics of the effect on human health Aive an e#ample of another effect on human health and a nonDhealth e#ample on

humans. tate the effect of e#cessive consumption of alcohol

4marks !ANSWER

(a)D %lcohol causes a poor


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Science SPM Paper 2 (Essay question) E

CHAPTER 3: HEREDITY AND VARIATION

H tudy the following statement.

There are two different shapes in the ear lobes of the students in a class.

(a) "sing the student population in a class, suggest a hypothesis to study the above statement.1mark !

(b) @escribe an e#periment in your classroom to test your hypothesis according to the followingcriteria.

%im of e#periment 1 mark ! &dentification of variables 2 marks ! 'ist of apparatus and materials 1 mark ! rocedure 2 marks ! Tabulation 1 mark ! %nalysis of data 1 mark ! onclusion 1 mark !

ANSWER

(a) The shape of the ear lobe is a discontinuous variation which can be clearly classified into the free earlobe or the attached ear lobe.(b) %im+ To study the shape of the ear lobe among the pupils.

ariables that are(i) manipulated+ different students in the class room(ii) responding+ type of ear lobe(iii) constant+ normal humans

'ist of apparatus and materials+ number of students in the class, figure of the shape of ear loberocedure+

3. Aroup the pupils in pairs.0. Based on the figure of the shape of ear lobe, determine the shape of the ear of their friend.

. ecord the results in the table below.

Tabulation+hape of ear lobe %ttached ear lobe Cree ear lobe

Tallying

/umber ofoccurrences

%nalysis of data+ @raw a bar chart of number of occurrences vs shape of ear lobe.



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onclusion+ The shape of ear lobe is discontinuous variation.

E

(a) The figures (a) and (b) show the formation of twins. /ame the types of twins and state threedifferences about the types of twins

0marks !

(b) % normal married couple wishes to have a baby boy. 9#plain the mechanism of se# determinationof a baby.:our answer should includes the following &dentify which gamete could determine the se# of a baby

larify the chromosomes which determine baby boy @raw the genetic chart for the se# determination in the baby The percentage of getting a baby boy for the couple.

4marks !



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ANSWER

(a)Cigure (a) Cigure (b)

&dentical twins /onDidentical twins;ne single ovum is fertili?ed by onesperm to form one ?ygote, then divides

into two ?ygotes

Two ova are fertili?ed by two sperms,forming two ?ygotes

Two foetuses sharing one placenta Two separate placentas, one for each foetusBoth have similar genetic content Both have different genetic content

(b) The father>s sperms determine the se# of a baby.% baby which inherits a : chromosome from its father, will be a boy. &f it inherits a I chromosome fromits father, it will be a girl.

The percentage of getting a boy is J.

1 (a) @efine mutation and mutagen.@escribe t o factors that cause mutation.

0marks !(b) The figure below shows mutation which happens in the body cell of human.

tudy the abnormalities caused by mutation above. 9#plain how you can built a concept based onthe information in the figure above.:our e#planation of the concept should include the following+ &dentify two common characteristics 2 marks ! @evelop initial concept 1 mark ! Aive another e#ample and a nonDe#ample in relation to the concept 2 marks ! 9#plain the actual concept 2 mark !



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ANSWER

(a)D =utation is a change in the genes or chromosomes that can alter the original traits of organisms.D =utagen is a substance or radiation that can induce or cause mutation.D /uclear radiation such as alpha, beta, gamma and harmful ray can penetrate the nucleus of a cell

and change the structure of the genes and chromosomes.D hemicals such as mustard gas, ben?ene and dio#ins can react with @/% in the chromosomes

(b)ommon characteristics

D %dditional or deletion of one chromosomes in the human body cell compare to the normal human bodycell.

D The difference in the number of chromosomes occur during meiosis to produce gametes with eithermore or less the number of chromosomes

&nitial conceptD The change of the number or the structure of chromosomes is called chromosome mutation.;ther e#ampleD Flinefelter>s syndrome

/onDe#ampleD %lbinism - colour blindness - sic7le cell anaemia%ctual concept

D hromosome mutation is the result of the changes in the number or structure of chromosomes

11 (a) tate t o advantages and t o disadvantages of genetic research to humans.0marks !

(b) % local ubang 4 papaya fruit is big but is less favourable to consumers.9#plain how =% @& solves the problem in increasing the consumption of local fruit.

:our answer should include the following+

&dentify the problem 1 mark ! larification of the traits of local papaya fruit and imported variety. 2 marks ! /ame the solving method. 2 marks ! tate the favourable trait of the product. 1 mark !

ANSWER

(a) %dvantages +1. genetic research has produced better medicines and vaccines for medical treatment.2. genetic research has improved the 6uality of crops and livestoc7.@isadvantages+

1. genetic research may lead to e#tinction of species as new varieties replace them.2. genetically modified food may be harmful to human health.(b)D The local papaya is less favourable to the consumer.D The traits of a local papaya are its big si?e, less sweet taste and has average thic7 flesh.D The traits of an imported variety are its fragrant smell, sweetness and small si?e when plantedlocallyD elective breeding is done between 'ocal ubang 4 papaya and *awaiian unrise olo papayato produce a new variety named 97soti7a =alaysia.D 97soti7a =alaysia is sweet, smells fragrant with thic7 fresh and is average in si?e.



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CHAPTER 4: MATTER AND SUBSTANCES

12 The melting point of an ionic substance is higher than a molecular substance.:ou are given lead bromide and naphthalene.

arry out an e#periment to prove the statement.:our answer should include the following+

(a) %im of e#periment. 1 mark !(b) *ypothesis of e#periment. 1 mark !(c) 'ist all variables. 3 marks !(d) rocedure. 3 marks !(e) @ata tabulation. 2 marks !

ANSWER

(a) To show that the melting point of lead bromide is higher than the melting pointof naphthalene.

(b) The melting point of an ionic substance is higher than a molecular substance.(c) =anipulated variable + 'ead bromide and naphthalene. esponding variable + =elting point onstant variable + =ass of substance heated.(d)

2 g of lead bromide is placed in a crucible. % thermometer is placed in the substance.

The substance is heated. The temperature at which the substance melted is recordedThe e#periment is repeated by using 2 g of naphthalene.(e)

ubstance 'ead bromide /aphthalene=elting point ( o ) *igher than 1 o 'ower than 1 o



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13 %n ionic substance is an electrolyte whereas a molecular substance is not.:ou are given sodium chloride and sugar.

arry out an e#periment to prove the above statement.:our answer should include the following+

(a) %im of e#periment. 1 mark !(b) 'ist all variables. 3 marks !(c) rocedure. 2 marks !(d) @ata tabulation. 2 marks !(e) 9#planation of the result of e#periment. 2 marks !

ANSWER

(a) To show that an ionic substance conducts electricity whereas a molecular substancedoes not.

(b) =anipulated variable + odium chloride a6ueous solution and sugar solution.

esponding variable + 'ighting of bulb. onstant variable + =ass of substance dissolved in cm 3 of water.(c)

1 gram of sodium chloride and 1 g of sugar are dissolved in cm 3 of water in separate bea7ers. Two carbon electrodes are immersed into each of the solution.The electrodes are connected to a dry cell. The lighting of the bulb is noted.

(d)olution odium chloride ugar

;bservation Bulb lights up. Bulb does not light up

(e) The sodium chloride solution consists of free moving ions that carry charges. Thus it

conducts electricity. The sugar solution consists of molecules which does not carry charges. Thusthe solution is a nonDelectrolyte.



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CHAPTER 5 : ENERGY AND CHEMICAL CHANGE

10 odium is more reactive than carbon. @escribe how the metal sodium can be e#tracted fromsodium chloride. :our answer should include the following+

(a) &dentifying the problem. 1 mark !

(b) /ame the principle used. 1 mark !(c) %n apparatus which shows the apparatus setDup. 2 marks !(d) rocedure. 2 marks !(e) ;bservations. 2 marks !(f) rite word e6uations for reactions ta7ing place. 2 marks !

ANSWER

(a) *ow is sodium metal e#tracted from sodium chloride saltG(b) odium is e#tracted from the electrolysis of molten sodium chloride.(c)

(d) odium chloride is heated until it melts. 9lectricity is passed through the molten sodiumchloride using carbon as electrodes.(e) %t anode + Areenish chlorine gas is released. %t cathode + ilver sodium metal is formed.(f) %t anode + hloride ion chlorine gas K electron %t cathode + odium ion K electron sodium metal

1 L hemical energy can be converted into electrical energyM.@escribe an e#periment to prove the above statement.:our answer should include the following+

(a) %im of e#periment. 1 mark !(b) /ame the principle used. 2 marks !(c) %n apparatus which shows the apparatus setDup. 2 marks !(d) rocedure. 2 marks !(e) ;bservation. 1 mark !(f) rite word e6uations for reactions ta7ing place. 2 marks !



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Science SPM Paper 2 (Essay question) 1H

ANSWER

(a) To show that chemical energy can be converted into electrical energy.(b) hen two different metal electrodes are immersed into an electrolyte, electrical energy is

produced.(c)

(d) 8inc and copper electrode are immersed into copper sulphate solution. The two electrodes are connected with a connecting wire to a galvanometer.(e) The needle of the galvanometer deflects.(f) %t ?inc electrode+ 8inc ?inc ion K electron %t copper electrode+ opper ion K electron copper

14 @escribe an e#periment to show that the reactivity of magnesium N ?inc N lead N copper.



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:our answer should include the following+

(a) %im of e#periment. 1 mark !(b) /ame the principle used. 1 mark !(c) %n apparatus which shows the apparatus setDup. 2 marks !(d) rocedure. 0 marks !

(e) Tabulation of results. 2 marks !

ANSWER

(a) To determine the relative reactivity of magnesium, ?inc, lead and copper.(b) The more reactive the metal the brighter is the reaction of the metal with o#ygen.(c)

(d) otassium permanganate( &&) is placed into a boiling tube. ome glass wool is then pushed into the tube. ome magnesium powder is added into a porcelain boat and then placed in the tube. The magnesium powder is heated strongly followed by heating the potassium permanganate( &&).

The reactivity of the reaction is recorded. 9#periment is repeated by replacing magnesium powder with other metal powders.(e)

=etal ;bservation=agnesium Burns very brightly

8inc Burns brightly'ead Alows brightlyopper Alows dimly

CHAPTER 6 : NUCLEAR ENERGY



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Science SPM Paper 2 (Essay question) 1E

1H (a) @escribe how electricity is generated in a nuclear power station.4marks !

(b) Aive two advantages and two disadvantages of using radioisotopes to generate electricity.0marks !

ANSWER

(a)chematic of a /uclear ower lant

"raniumD23 atoms are bombarded with neutrons. (1)The uranium atoms undergo fission with release of heat energy. (1)The heat energy is used to heat water into steam. (1)The steam produced will turn the turbine to generate electricity. (1)The electricity produced is then transmitted to consumers via electric cables. (1)(b) %dvantages The radioactive fuel lasts a long time. % small 6uantity of radioactive substance can generate large amounts of energy. @isadvantages The gamma radiations emitted can cause cancer. roblems faced from storage of the by products as they continue to emit radiations

for a long time.

15 (a) ith e#amples e#plain the difference between isotopes and radioisotopes.YL KONG @SMKSARA OK2!!"


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0marks !

(b) 9#plain the uses of radioisotopes in the field of

(i) medical(ii) industry

(iii) agriculture3marks !

(c) tate three precautions we have to ta7e when handling radioisotopes.3marks !

ANSWER

(a)&sotopes are atoms with the same number of protons but different number of neutrons.

adioisotopes are isotopes that are radioactive and can undergo spontaneous decay.Cor e#ample, carbon has carbonD12 and carbonD10 isotopes.The carbonD10 isotope is unstable and decays spontaneously.&t is a radioactive isotope.(b)(i) Aamma radiation from the decay of uraniumD23 is used to sterili?e medical e6uipments andmedicines.(ii) Aamma radiation from the decay of uraniumD23 is used to detect canned food which is

partially filled.(iii) Aamma radiation from the decay of radioactive phosphorusD32 is used to study the rate of absorption of phosphate fertili?er by plants.(c)

ear protective lead clothings and gloves.

"se a dosimeter to measure the intensity of the radiation."se remote control arms to handle the radioisotopes.

CHAPTER 7 : LIGHT, COLUR AND SIGHTYL KONG @SMKSARA OK2!!"


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15 tudy the following statement.

hen white light is shone on two different primary coloured filters, no coloured light passesthrough, but when white light is shone on two different secondary filters, a certain coloured light

passes through.

(a) uggest a hypothesis to investigate the above statement. 1mark !(b) "sing a red filter, a blue filter, a magenta filter, a yellow filter and other apparatus, describe an

e#periment to test your hypothesis in (a) based on the following criteria$ %im of e#periment 1 mark ! &dentification of variables 2 marks ! 'ist of apparatus 1 mark ! rocedure 0 marks ! Tabulation of data 1 mark !

ANSWER

(a) % primary colour filter only enables its coloured light to pass through it and to absorb all other colour lights but a secondary colour filter enables its colour and the primary colour lights that form it to passthrough it.(b) %im of the e#periment+ To study absorption - subtraction of coloured light by a primary filter.

ariables that are+(i) manipulated + the colour filter used(ii) responding + the colour on the white screen(iii) constant + white light from ray bo#%pparatus+ 'ight bo#, glass prism, a red filter, a blue filter, a magenta filter, a yellowfilter and white screen.

rocedure+

1. The apparatus as shown above is set up.2. The light bo# is switched on. The position of the white screen is ad


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0marks !

(b) The figure below shows several characteristics formed by an optical apparatus.

tudy the characteristics of the image formed. 9#plain how you can determine the apparatus usedand the phenomenon that occurred in the formation of the image based on the information in thefigure above.:our e#planation of the phenomenon should include the following+

&dentify two criteria in the formation of the image &dentify the apparatus and develop the phenomenon Aive other e#ample and nonDe#amples of the characteristic of the image 9#plain the 'aw of the phenomenon.

4 mar7s!

ANSWER

(a)roperties of the image onve# lenses oncave lenseseal or virtual eal if the ob


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2 (a) ompare and contrast the focusing and controlling of the amount of light in the humaneye and a camera.

0marks !

(b) % student wants to observe a distant ob


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21 teel is harder than pure iron.arry out an e#periment to prove the above statement.

:our e#planation must include the following+

%im of the e#periment 1 mark ! *ypothesis. 1 mark ! &dentification of variables. 3 marks ! rocedure 3 marks ! Tabulation of data 1 mark ! onclusion 1 mark !

ANS!ER

(a) To compare the hardness of steel and pure iron.(b) teel is harder than pure iron.(c) =anipulated variable + teel bloc7 and pure iron bloc7 esponding variable + @iameter of dent onstant variable + *eight the weight is dropped onto the ball bearing.(d) % steel ball bearing is fi#ed onto a steel bloc7 using cellotape. % 1 7g weight is dropped onto the ball bearing from a height of cm. The diameter of the dent produced is measured, using a ruler. The e#periment is repeated by replacing the steel bloc7 with pure iron bloc7.(e)

=aterial teel bloc7 ure iron bloc7

@iameter of dent (cm) p mm 6 mm

(f) The value of 6 N p. e conclude that pure iron is softer or steel is harder.

22 (a) @escribe how ammonia is synthesi?ed in industry.YL KONG @SMKSARA OK2!!"


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:our answer should include the following+(i) /ame the process.(ii) tate the sources of reactants.(iii) ;ptimum conditions to synthesi?e ammonia(iv) ord e6uation to represent the process

Hmarks !

(b) tate three uses of ammonia.3marks !

ANS!ER (a) (i) *aber process (1) (ii) /itrogen is obtained from fractional distillation of li6uid air. *ydrogen is obtained from natural gas. (2) (iii) ressure of 2 atmosphere, temperature of 0 o

and iron powder is used as catalyst. (3) (iv) /itrogen K hydrogen ammonia (1)(b) To ma7e fertili?er, nitric acid and prevent coagulation of late#. (3)

23 (a) @efine what is an alloy. 2 marks !(b) Aive an e#ample of alloy and its composition. 2 marks !(c) tate a use of the alloy in (b) above. 1 mark !(d) 9#plain using the arrangement of atoms, why an alloy is harder than its pure

metal.marks !

ANS!ER (a) %n alloy is a mi#ture of two or more metals in a certain percentage.(b) Bron?e. (E J copper and 1 J tin)

(c) Bron?e is used to ma7e medals.(d)

The atoms in pure metals are arranged in a regular pattern. hen a force is applied to it, theatoms will slide across each other. Thus pure metal is soft. (2)

The diagram above shows the presence of foreign atoms in an alloy. The foreign atoms preventthe metal atoms from sliding when a force is applied to it.Thus alloy is harder. (1)

FOR" # $C%a&t'r 1 ( "icroor)ani*+* an, t%'ir '--'ct* on livin) t%in)*YL KONG @SMKSARA OK2!!"


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1 tudy the following statement$

unlight affects the activities of microorganisms

uggest a hypothesis to investigate the above statement. 1 mark !

(b) "sing few petri cultures of Bacillus subtilis, describe an e#periment to test your hypothesis in (a) based on the following criteria$

%im of the e#periment 1 mark ! &dentification of variables 2 marks ! 'ist of apparatus and materials 1 mark ! rocedure 3 marks ! Tabulation of data 1 mark ! onclusion 1 mark !

Answ !

1 (a) Hy&ot%'*i*: trong sunlight 7ills - stops the activities of microorganisms

(b) Ai+: To study the effect of sunlight on the activities of microorganism

Con*tant varia.l': /utrient - p* of the nutrient - amount of bacteria"ani&ulat', varia.l': e#position to lightR'*&on,in) varia.l': number of bacteria coloniesA&&aratu* an, +at'rial*: 3 petri cultures of Bacillus subtilis with their sterile covers,Proc',ur':

(i) The 3 petri dishes with culture of Bacillus subtilis were covered with their sterilecovers respectively and overturned.

(ii) The dishes were labelled %, B and . etri dish % was put inside a dar7 cupboard. etri dish B was put on the lab table and etri dish was put under the ultraviolet light.(iii) The dishes were left aside for 2 days.(iv) The observation was recorded.

Ta.ulation o- ,ata:etri dish ;bservation

%B

Conclu*ion:etri dish % shows the number of bacteria colonies and etri dish shows none. unlight stops

the activities of the microorganism. *ypothesis is accepted.



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2 (a) Bacteria and alga are microorganisms. omehow there are differences between the twomicroorganisms. tate four differences in the properties between bacteria and alga.

0marks !

(b) The figure above shows two loaves of bread % and B made by two students % and Brespectively.

tate the difference between bread % and bread B.

@escribes how student B can ba7e bread li7e student %. :our e#planation must have thefollowing criteria+ roblem statement /ame the ingredient needed tate how the action of the ingredient helps to ba7e a better bread

4marks !

ANS"ER :2(a)

roperties Bacteria %lgai?e -Qm . D1 1 D 1hape od, sphere, comma, spiral ariety shape

"nicellular -=ulticellular

"nicellular =ulticellular

/utrition aprophyte, parasite andautotroph

%utotroph

(b)Bread % is light and fluffy but bread B is small and hardBread B lac7s one ingredient that ma7es the dough not rise and not fluffy.:east:east brea7s down the glucose in the bread dough and releases carbon dio#ide gas.

arbon dio#ide gas ma7es the dough rise and the bread becomes light and fluffy.



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3 (a) "sing heat or chemical are two ways of sterili?ation. @escribe two methods for each wayto show how sterili?ation is carried out.

0marks !

(b) tudy the picture above and construct a concept of how transmission of disease occursthrough a vector.

:our answer must be based on the steps below+ &dentify the common characteristics 2 marks elate the common characteristics to the transmission of disease through

the vector in order to construct the initial concept 1mark Aive an e#ample of another transmission of disease through the vector

and a transmission of disease not through the vector 2marks tate the actual concept of transmission of disease through the vector. 1 mark

ANS"ER :

3(a) *eat +

1 + Boiling in water at 1 R for 4 hours2 + *eating for 1 minutes in the autoclave at 121R

hemical +1+ %ntiseptic applied on in


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CHAPTER / ( Nutrition an, -oo, &ro,uction

0lants do not grow healthily when lac7ing in certain nutrients

(a) Based on the above statement and using the minerals of nitrogen, phosphorous, and potassium, write one suitable hypothesis.

1mark !(b) "sing a complete culture solution, culture solution without nitrogen, culture solution

without phosphorous, culture solution without potassium and other apparatus, describe ane#periment that you carry out in the laboratory to prove the hypothesis.

:our description should include the following$

aim of e#periment 1 mark !identification of variables 2 marks !list of apparatus and materials 1 mark !

procedure 0 marks !tabulation of data 1 mark !

ANSWER :

0(a) @eficiency in nutrient nitrogen, phosphorous and potassium hinder the growth of plants.

(b) %im + To study the effects of nitrogen, phosphorous and potassium deficiency on the plantgrowth.

Con*tant varia.l' : germinating seed, fre6uency of changing solution"ani&ulat', varia.l' : culture solutionR'*&on,in) varia.l' : rate growth of germinating seedA&&aratu* an, +at'rial* : cotton, blac7 paper, germinating seeds, complete culture solution,culture solution without nitrogen, culture solution without phosphorous, culture solution without

potassium, measuring cylinder and 0 boiling tubes

Proc',ur' :1) 0 boiling tubes were labelled and filled with culture solution as shown below+



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2) =ouths of boiling tubes were closed with cotton and one germinating seed was put in eachtube.

3) 9ach boiling tube was wrapped with blac7 paper.0) %ll the boiling tubes were put on a rac7 and left e#posed to sunlight.

) %fter a wee7, the culture solutions were changed to new ones.4) ;bservation of each germinating seed was done for two wee7s and the results were

recorded.

Tabulation of dataBoiling tube ;bservation

%B

@

(a) The calories re6uirement per day of the two people in the figure below is not the same.&dentify the factors that affect the calories re6uirement per day for the individuals

below.

Aive three e#planations how they affect the calorie re6uirement per day.0marks !

(b) The figures below show three different diseases caused by malnutrition.



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Cigure (i) + ic7etts Cigure (ii) + curvy Cigure (iii) + Aoiter

tudy the diseases in the figures above and e#plain how you construct the concept ofmalnutrition.:our answer should be based on the following steps+ &dentify the information &dentify the common characteristics elate the common characteristics to malnutrition in order to construct the initial

concept Aive other e#amples and nonDe#amples in relation to the concept

tate the actual concept of malnutrition 4marks !ANS"ER:

(a) se#% man re6uires more calories than a lady because$(i) si?e and weight of a man is bigger than a lady(ii) metabolism of a man is higher (iii) a man is more active physically

(b)&dentify the information The diseases are caused by malnutrition for a

long period of time&dentify the commoncharacteristics

The diseases above are due to deficiency of oneclass of food respectively in daily diet.(i) ic7etts D deficiency of vitamin @(ii) curvy D deficiency of vitamin (iii) Aoiter D deficiency of iodine

elate the commoncharacteristics to malnutritionin order to construct theinitial concept

@eficiency of one class of food in daily dietmay lead to malnutrition.

;ther e#amples

/onDe#amples

Fwashior7or - %nemia - /ight blindness

;besity - %rteriosclerosis - @iabetestate the actual concept of

malnutrition=alnutrition is a state when an individualsuffers from food deficiency in one or twonecessary food classes in his daily diet tomaintain a healthy body.



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CHAPTER 0$Pr'*'rvation con*'rvation o- t%' 'nviron+'nt

4

The figure above shows =r. Sohnny>s farm. *e plants leafy vegetables, rear fresh water fish and poultry for sale. *e uses chemical fertili?ers and pesticides to maintain and increase the yield of his vegetables.

tate the four effects of e#cessive use of chemical fertili?ers and pesticides.0mark

%fter some time, he finds that the surface of the pond is covered with a layer of green substanceand the fish has died.9#plain how =r. Sohnny overcomes the problems in his pond.:our answer should include the following$ &dentify the problem tate the phenomena larification of the problem olving methods

4markANS"ER :4.9#cessive fertili?er that flows to river and pond encourages the growth of alga.%lga prevents sunlight from reaching the bottom of the river or pond, a6uatic plants cannotundergo photosynthesis and therefore die.The content of o#ygen in the water decreases.

esticides hardly decompose, but flow into the pond or river and are eaten by the a6uaticanimals, causing death or passing on into the food chain.

&dentify problems %lga grows on the water surface and the dieshenomena 9utroficationlarification of the

problem9#cessive fertili?er and waste from the poultry contain nitrate and

phosphate compounds which encourage the growth of alga. esticidesfrom the vegetable farm contain @@T which is harmful to livingorganisms.

olving methods onvert the poultry waste into compost fertili?er. "se compostfertili?er instead of chemical fertili?er"se biological pest control methods instead of pesticides.



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H (a) &mproper management of open land to give way for development has caused a number of side effects on the balance in nature.

tate four side effects caused by improper management of open land.0marks !

(b) The figures (i) and (ii) below show activities which happened in our surroundings that

caused global warming.

tudy the above activities. 9#plain how you would be able to construct the concept of

global warming.:our answer should be based on the following steps+ &dentify the common characteristics elate the common characteristics to the change of environment in order to construct

the initial concept Aive an e#ample of other forms of pollution and a nonDe#ample in relation to the

concept. tate the actual concept of global warming

4marks !

ANS!ER :23a4 e#tinction of species

loss of habitatsoil erosionflash flood

(b)&dentify the commoncharacteristics

ombustion of fuel release carbon dio#ide into the air.utting down of trees eliminates the process of photosynthesis

of the trees, indirectly increasing the content of carbon dio#idein the air

onstruct the initialconcept arbon dio#ide in the air prevents heat from leaving theatmosphere, thus increasing the temperature on the earth whichis named global warming

%nother e#ample /on e#ample

Corest fire - open burning of rubbish@isposal of byproducts, waste, to#ic substances, radioactivesubstances, smo7e and heat - uncontrolled use of chemicalfertili?ers

tate the actual conceptof global warming

Alobal warming is the rise in earth temperatures due to theincrease of greenhouse gases li7e carbon dio#ide.



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CHAPTER 5 ( Car.on Co+&oun,*

5 % rubber planter adds ammonia into late# to maintain its li6uid state and sells it in li6uid state.To some late#, he adds formic acid and sells it as solid rubber.

(a) Based on the above statements, write one suitable hypothesis.1mark !

(b) ith the material of late#, acetic acid and ammonia, describe an e#periment that you cancarry out in a laboratory to prove the hypothesis.:our description should include the following$

(i) aim of e#periment 1 mark !(ii) identification of variables 2 marks !(iii) list of apparatus and materials 1 mark !(iv) method 3 marks !(v) how to tabulate the data 1 mark !

(vi) conclusion 1 mark !

ANS!ER :

5(a) Hy&ot%'*i* + %l7aline prevents coagulation of late# and acid coagulates the late#.

(b) (i) To study the effects of al7aline and acid on late#(ii) +ani&ulat', varia.l'*: ammonia and acetic acid r'*&on,in) varia.l'*: condition of late# - coagulation of rubber con*tant varia.l'*: volume of late#(iii) a&&aratu* an, +at'rial* + late#, acetic acid, ammonia, bea7er, measuring cylinder

(iv) +'t%o,: 1. 'ate# is measured with a measuring cylinder and poured into 2 bea7ers2. %mmonia and acetic acid are poured into the respective bea7ers.3. The mi#tures are stirred and left for 1 minutes. ;bservations are recorded.

(v) 6ataBea7er ;bservation%B

(vi) Conclu*ion + %mmonia prevents the late# from coagulating and acid causes coagulation oflate#



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E (a) tate three differences between organic carbon compound and non organic carboncompound. /ame an e#ample for each respective group.

0marks !(b) The figure below shows the products of hydrocarbon.

tudy the products above and construct the concept of hydrocarbon.:our answer should be based on the following steps$ &dentify two common characteristics @evelop initial concept Aive an other e#ample and a nonDe#ample in relation to the concept 9#plain the actual concept

4marks !ANS!ER:

E (a) ;rganic carbon compound /on organic carbon compoundarbon compound which has

originated from living organisms.arbon compound which has originated from

non living thing such as minerals.arbon chain which has many carbon

atoms.=olecule with few carbon atoms only.

@issolve in organic solvent.9g+ alcohol

@issolve in nonDorganic solvent9g. water

tarch arbon dio#ide (b)

ommon characteristics The products are hydrocarbon compound which

consists of carbon and hydrogen elements.The products have originated from living organismswhich died millions of years ago

&nitial concept The products are from the sources of fossil fuel9#ample

/onDe#ample /atural gas=ineral such as calcium carbonate

%ctual concept *ydrocarbon is organic carbon compound whichconsists of the carbon and hydrogen elements andhas originated from living organisms which diedmillions of years ago



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1 (a) Butter and margarine are used to made ca7es and coo7ies.tate four differences between butter and margarine based on the following$

ources tructure of atom hysical properties 9ffect on health

0marks !

(b) %n officer whose favourite foods are ca7es and coo7ies, finds that her low densitycholesterol level in the blood test is slightly higher.9#plain how the officer can solve or remedy her situation since she cannot give up her favorite foods.:our e#planation should include the following$ roblem statement tate the effects on the body uggest a diet to replace the present diet

4marks !

ANS!ER :

1 (a)Butter =argarine

ources animal lanttructure of atom aturated fat with single bond

between carbon atom"nsaturated fat with at leastone double bond betweenthe carbon atom

hysical properties olid at room temperature 'i6uid at room temperature9ffect on health &ncrease level of cholesterol @ecrease level of

cholesterol(b)

'ow density cholesterol in the blood is slightly high. 'ow density cholesterol deposits on gall bladder as gall bladder stones 'ow density cholesterol deposits on the insides of the wall of the artery may cause

high blood pressure, heart disease, arteriosclerosis and coronary thrombosis "se margarine in ma7ing the ca7e and coo7ies %dd fiber, fruits and, vegetables such as carrot into the ca7e 9g+ %pple ca7e, arrot ca7e



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CHAPTER # $ "otion

% moving heavy vehicle has higher momentum

Based on the statement above, suggest a hypothesis.

1mark !

(b) "sing four trolleys, an inclined plane, a wooden bloc7, plasticine and other apparatus,describe an e#periment to test your hypothesis in (a) based on the following criteria+(i) aim of e#periment 1 mark !(ii) identification of variables 2 marks !(iii) list of apparatus and materials 1 mark !(iv) procedure 0 marks !(v) tabulation of data 1 mark !

ANS!ER :11(a) *ypothesis+ The bigger the mass of moving ob


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3

% big ship is made of a mi#ture of iron. The figures above show that a piece of ironsin7s into the sea whereas a big ship floats on the sea.9#plain why.

0marks !

% student ma7es a simple hot air balloon model as shown above for his science pro principle.Solvin) +'t%o,*:0. &ncrease the si?e of the balloon to displace more cool air by the hot air inside the balloon.



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. % bunsen burner is lighted at the bottom of the balloon to heat the air inside the balloon.

CHAPTER 7 ( Foo, t'c%nolo)y an, &ro,uction

rocessed food can last longer than nonDprocessed food if left e#posed to open air

Based on the statement above, suggest a suitable hypothesis.

"sing a fresh nonDprocessed mil7, a boiled mil7, a pasteurised mil7 and other apparatus,describe an e#periment to test your hypothesis in (a) based on the following criteria+

%im of e#periment 1 mark ! &dentification of variables 2 marks ! 'ist of apparatus and materials 1 mark ! rocedure 3 marks ! Tabulation of data 1 mark ! onclusion 1 mark !

ANS!ER :10 (a) *ypothesis+ rocessed food can last longer than nonDprocessed food if left e#posed to

open air.(b)%im + To identify the processed food that can last longer than nonDprocessed food.

ariable that is$(i) manipulated + the method of processed mil7 (ii) responding+ the condition of the mil7 (iii) constant+ the volume of mil7

'ist of apparatus and material+ fresh nonDprocessed mil7, boiled mil7, pasteurised mil7, 3 bea7ers, measuring cylinder

rocedure+1. Three sterile bea7ers are prepared. Bea7er % is filled with fresh nonDprocessed mil7, bea7er B

is filled with boiled mil7 and bea7er is filled with pasteurised mil7.2. The bea7ers are left in the open air for one day.3. ;bserve the condition and the smell of the mil7 after one day and record in the table below.

esult+Bea7er ;bservation

%B

onclusion+ /onDprocessed mil7 becomes rotten faster than boiled and pasteurised mil7. asteurised mil7lasts longer than fresh nonDmil7 and boiled mil7.



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The world population growth is much faster than the production of food. 9#plain how the property of 6uality breeds can help to increase the production of food.

% vegetable farmer found his farm is no longer productive and is having problems with a pest on his farm.9#plain how the farmer on his farm can overcome his problems on his farm.

:our answer should include the following$

%im of e#periment 1 mark ! larification of the problem 1 mark ! olving methods 3 marks ! hoose the best method and e#plain your choice 1 mark !

ANS!ER :15(a) roperty of 6uality breeds+(i) high 6uantity of production(ii) high 6uality of production(iii) short production period(iv) high resistance towards disease and pest

(b)&dentify the problem The farmer>s farm is no longer productive and

is attac7ed by a pest.larification of the problem The soil is not fertile anymore due to intensive

use by certain 7ind of plant.The pest has formed a high resistance towardsthe pesticide used.

olving methods rop rotation to regain the fertility of the soil.=i#ed crops to regain the problem of the pestand at the same time can regain the fertility of the soil.&ntegrated system that is to rear poultrytogether with plants.

Best method =i#ed crops to reduce the problem of the pest,and at the same time can regain the fertility of the soil.



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CHAPTER 2 ( Syt%'tic "at'rial* in t%' in,u*try

ynthetic rubber is not easily burned compared to natural rubber

14 (a) uggest a hypothesis to investigate the above statement1mark !

(b) "sing a synthetic rubber strip, a natural rubber strip and other apparatus, describe ane#periment to test your hypothesis in (a) based on the following criteria+

%im of e#periment 1 mark ! &dentification of variables 2 marks ! 'ist of apparatus and materials 1 mark ! rocedure 3 marks ! Tabulation of data 1 mark ! onclusion 1 mark !

ANS!ER :17(a) *ypothesis + /atural rubber burns more easily than synthetic rubber

(b) %im + To compare the characteristic of synthetic rubber and natural rubber towards burning.

ariable that is$(i) manipulated+ type of rubber (ii) responding+ ability to burn(iii) constant+ time of heating'ist of apparatus+ a synthetic rubber strip, a natural rubber strip, Bunsen burner, tongs

rocedure +

1. % synthetic rubber strip is burned with a Bunsen burner for minutes as shown above. Theobservation is recorded.

2. % natural rubber strip is burned with the same Bunsen burner for minutes. The observationis recorded.

Tabulation of data+haracteristic ynthetic rubber /atural rubber

%bility to burn /ot easily burnt Burns with lots of soot

onclusion+ /atural rubber burns easily with lots of soot whereas synthetic rubber does not burn easily.*ypothesis is acceptable.



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1H (a) The figure above show the products of thermoplastic. tate four reasons why theabove products are thermoplastic and not thermoset.

0marks !

(b) % local council found that the rubbish dumped by the public mostly is made of plastic.9#plain how the local council can solve the problem of disposal of plastic rubbish.:our e#planation should include the following+

&dentify the problem 1 mark ! larification of the problem 1 mark ! olving methods 3 marks ! hoose the best method and e#plain your choice 1 mark !

ANS!ER :12

(a) D the products have low resistance toward heatD the products are softD the products can be recycled as the material can be moulded few timesD the products do not have cross lin7age between the polymers chainD the products have low melting point

any 0 points!(b)

&dentify the problem lastic rubber is not biodegradable and causesenvironmental pollution.

larification of the problem *ow can we reduce environmental pollutioncaused by plastic rubbishG

olving methods 3. "se biodegradable plastic which can bedecomposed by microorganism.

0. Burn the disposed plastic in an incinerator.. ecycle the disposed plastic into plastic

product that can be used again4. euse the plastic for other purposes.

hoose the best method ande#plain your choice

ecycle because thermoplastic can be mouldeda few times as it can reduce the disposal of

plastic and save sources of plastic raw materials



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15 (a) olymer synthetic is very useful in modern life. @escribe four negative effects of theconsumption and disposal of polymer synthetic in the environment.

1mark !

(b)

The figure above show the plastic which can be recycled. tudy the information aboveand construct the concept of recycling. :our answer should be based on the following

steps+ &dentify two common characteristics 2 marks ! @evelop initial concept 1 mark ! Aive an e#ample of another recycleable and nonDrecycleable

plastic2marks !

tate the actual concept of recycleable plastic 1 mark !

ANS!ER:18(a) (i) olymer synthetic is not biodegradable and it will be in the environment for a long

period which may cause environmental pollution.

(ii) ;pen burning of polymer synthetic releases soot and to#ic gases such as dio#in whichmay cause air pollution and public health problem. (iii) @isposal of plastic in the drainage may cause bloc7age of drainage system and flash flood. &t may encourage the breeding of mos6uitoes. (iv) @isposal of plastic in sea and river may cause e#tinction of turtle and other a6uatic life.

(b)Two common characteristics The plastics can be repeatedly moulded into a variety

of shapes.The polymer chains of the plastic can slide from one

to another when heated and come together whencooled.&nitial concept lastic which can be recycled is the plastic which can

be repeatedly moulded into various shapes and the polymer chains can slide from one another whenheated.

9#ample /on e#ample

olypropene - polystyreneBa7elite - melamine - epo#y glue

%ctual concept Thermoplastic can be recycled for other purposes thatcan be moulded into new products



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CHAPTER 8$ El'ctric an, in-or+ation an, co++unication t'c%nolo)ytudy the following statement.

The brightness of a bulb varies with the number of resistors in a circuit.

1E (a) uggest a hypothesis to investigate the above statement.1mark !

(b) "sing three resistors, a bulb and other apparatus, describe an e#periment to test your hypothesis in (a) based on the following criteria$ %im of e#periment 1 mark ! &dentification of variables 2 marks ! 'ist of apparatus and materials 1 mark ! rocedure 3 marks ! Tabulation of data 1 mark ! onclusion 1 mark !

ANS!ER :1E(a) *ypothesis+ The more the number of resistors used in a circuit, the dimmer the

light of the bulb.(b) %im of the e#periment+ To study the effect of resistors on the brightness of a bulb.

ariable that is$(i) constant+ number of dry cell - power of the bulb(ii) manipulated+ number of resistors

(iii) responding+ the brightness of the bulb

'ist of apparatus+ 3 resistors, bulb, dry cell, connection wire and switch



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rocedure+

1. The above circuit is prepared.2. witch is on and the brightness of the bulb is observed.

3. % resistor is ta7en away and switch is on. The brightness of the bulb is observedagain.0. tep 3 is repeated with one resistor left.

. The results of the observations are recorded in the table below

Tabulation+ /o. of resistor Brightness of bulb

321

onclusion+%s the number of resistors decreases, the brighter the bulb is. *ypothesis is acceptable.

2! (a) % radio wave is used in long distance communication. Aive -our reasons why a radiowave is used in information communication.

0marks !

(b) The table below shows types of radio waves used in radio communication.'ocal radio broadcasts 'ong ave with low fre6uency

adio broadcasts across continent hort ave with high fre6uencyT %stro broadcasts =icrowaves

tudy the information in the table above and construct the concept of radiocommunication. :our answer should be based on the following steps+ &dentify the information 1 mark ! &dentify the common characteristics 2 marks ! elate the common characteristics to the radio communication in order

to construct the initial concept.1mark !

Aive an e#ample of another radio communication and a non radiocommunication

1mark !

tate the actual concept of radio communication 1 mark !YL KONG @SMKSARA OK2!!"


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ANS!ER:/9(a) D &t can travel through vacuum

D &t moves with the speed of light, so it can transmit the information very fast. D &t acts as a carrier wave for audio and video signals D &t is not easy to be spread through an obstruction

(b)&dentify the information 'ocal radio broadcast use the long wave with low

fre6uency of the radio wave as a carrier wave to deliver sound information

&dentify the commoncharacteristics

D adio broadcasts across continent use short waves withhigh fre6uency of the radio wave as a carrier wave todeliver sound information D T %stro broadcasts use microwaves with the highestfre6uency of radio wave as a carrier wave to deliver soundand picture information

elate the commoncharacteristics to theradio communication inorder to construct theinitial concept.

%ll the three radio communications above use the wave of different fre6uency of radio waves in electromagneticspectrum as the carrier wave to deliver information.

%n e#ample

/on e#ample

*and phone - C= radio broadcast

=icrowave oven%ctual concept of radiocommunication

adio communication is using a range of radio waves inthe electromagnetic spectrum as carrier to deliver information



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21 (a) tate -our advantages of satellite communication system to other communication system.0marks !

(b) Cootball orld up 2 4 was held in Aermany. % remote country could not get the livetelevision broadcasts for the tournament. 9#plain how the country can solve the problem

so that they can watch the matches live in the ne#t tournament.:our answer should include the following+

larification of the problem 1 mark ! /ame the system of communication 1 mark ! teps for the system to function 0 marks !

ANS!ER:21(a)D transmission or receiver of satellite system is not affected by the change in weather.D it can service a wide area including the remote areaD it does not need many relay station as microwave can move very far D it can deliver a lot of information 6uic7ly and efficientlyD it can transmit live broadcasts throughDout the world

(b)larification of the problem *ow to get live television broadcastsG

ystem of communication "se satellite communication system

teps of the system to function %n earth satellite station is built in the country.Television camera will record the match in the stadiumwhere and when the tournament is on.The electrical signal will be sent to the televisionstation and be transmitted by micro wave by the earthsatellite station of the host country to thecommunication satellite in space.The communication satellite in space will strengthenand transmit bac7 to the earth>s satellite station in theremote country, and then to the local television station.



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Science SPM Paper 2 (Essay question)



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