Gr 8 PhyScNov 2010
GRADE 8
PHYSICAL SCIENCE EXAM
NOVEMBER 2010
MARKS: 120TIME: 2 Hours
EXAMMINER: K WarneMODERATOR: P Westwood
INSTRUCTIONS and NOTES:
- This paper consists of 9 pages of questions.
- Ananswer sheet and a periodic table.
- Use a pencil where it is required.
- A scientific calculator may be used.
- Use the Answer sheet for ALL questions.
EQUATIONS
g = 10 N/kg
QUESTION 1MULTIPLE CHOICE
- Four possible answers indicated by A, B, C and D are supplied with each question. Choose only that answer which, in your opinion, is the correct or best one and mark the appropriate block on your answer sheet.Use a pencil ONLY.
- Each question has only one correct answer.If you make a mistake erase the wrong answer completely and mark the correct one. If more than one block is marked, no marks will be awarded for that answer.
- Which of the following is not a state of matter?
ALiquid B GasC SolutionD Solid
1.2Which of the following statements correctly describes pure water (H2O).
AIt is an element.
BIt is a compound.
CIt is a mixture.
DIt is a solution.
1.3Which of the following correctly describes the procedure to separate a mixture of sand and salt?
AFiltration then making a solution and evaporation.
BMaking a solution, filtration then evaporation.
CMaking a solution, evaporation then filtration.
DEvaporation, making a solution then filtration.
1.4Which of the statements below is NOT correct at room temperature?
AMost elements are metals.
BSome elements are gases.
CMany elements are liquids.
DVery few elements are liquids.
1.5A stone sinks in a measuring cylinder of water. This causes the volume of water in the cylinder to rise. If the density of the stone is 5 g.cm-3 and the volume of water in the cylinder rises by 10 cm3 then the mass of the stone (in grams) would be given by
A5 x 10 B C D 0.05 x 10
1.6Which of the following does NOT represents a chemical change?
AIron + sulphur iron sulphide
BWater hydrogen + oxygen.
CMercury oxidemercury + oxygen
DSalt Water salt + water
1.7Which of the following measurement units would be the most appropriate for measuring the the thickness of a piece of paper?
Ameters (m)
Bcentimeters (cm)
Ckilometers (km)
Dmicrometers (µm)
1.8If more solvent is added to a saturated solution then ...
AMore solute can be dissolved in it.
BMore solvent will evaporate.
CHeat will be given off by the solution.
DSome solid may crystallise out of the solution.
1.9For which one of the following gases is aglowing splint of wood used as a test?
AHydrogen
BOxygen
CCarbon dioxide
DNitrogen
1.10Watts are the unit of .....
AEnergy
BForce
CPower
DWork
1.11What is the energy transformation that takes place when a bicycle that is moving comes to a halt because the cyclist applies the brakes?
Akinetic to potential energy
Bpotential to kinetic energy
Cchemical to potential energy
Dkinetic to heat energy
1.12The mass of a 4g block of wood written in kilograms would be ...
A4000 kg
B0.4 kg
C0.004 kg
D0.04 kg
1.13Which of the following graphs apply to a spring that obeys Hooke’s law?
A B
CD
1.14Which of the following properties of light is shown by the fact that objects cast shadows?
AReflection
BLight travels in straight lines
CLight travels through space (a vacuum)
DNone of the above
1.15Which of the following is NOT a property of the image in a plane mirror?
ASame size
BUpright
CVertically inverted
DLaterally inverted
1.16When you burn your tongue on a hot drink the heat is transferred mostly by...
AConvection
BRadiation and convection
CRadiation
DConduction
1.17Which of the following statements correctly describes the way that objects radiate and absorb heat?
AA bad emitter of heat is a bad absorber of heat
BA bad emitter of is a good absorber of heat
CA good emitter of heat is a bad absorber of heat
DThere is no relationship between absorbing and emitting of heat.
17 x (2) = [34]
QUESTION 2ONE WORD/PHRASE ANSWERS
ANSWER ON THE ANSWER SHEET
Fill in the missing word or phrase that best describes or completes the sentences below:
2.1The colder the water the ______soluble gases become.(1)
2.2When carbon dioxide is bubbled through ______it becomes milky.(1)
2.3Potential energy is the ability that a body has to do work because of its ______(1)
2.4Springs and objects which return to their original length after being stretched, are said to be ______. (1)
2.5An ______substance is one which does not transmit light.(1)
2.6Heat is the ______that is transferred when a hot body is in contact with a cold body.(1)
[6]
TOTAL SECTION A: 40
SECTION BANSWER ON LINED PAPER PROVIDED
QUESTION 3PARTICLE THEORY
3.1What deduction can be made about the particles in gases and liquids from the observation of Browinian motion? (2)
3.2Statewhat happens (INCREASE or DECREASE) when water freezes to:
3.2.1the ENERGY of water molecules and (1)
3.2.2the SPACES between the water molecules. (1)
3.3Which state of matter does not exhibit diffusion?(1)
[5]
QUESTION 4PHYSICAL & CHEMICAL CHANGE
Complete the diagram below by placing the given words or terms in their correct places: (Words may only be used once.) Write the numbers 4.1 – 4.5 and then the correct word from the list below. (5)
Compound; physical change; elements, mixture; chemical change
4.6State one way that a chemical change is different from a physical change.(1)
4.7If a two graphite electrodes are placed into a solution of copper (II) chloride and connected to an electrical power source;
4.7.1State what would you would see at the negative electrode.(2)
4.7.2Write a word equation for the reaction that is taking place.(2)
4.7.3Is this reaction EXOTHERMIC or ENDOTHERMIC?(1)
[11]
QUESTION 5Mixtures & Separation
A person wishes to separate mixture of salt, water and sand. They decide to use filtration as their separation technique. They assemble the following apparatus: beakers, filter funnel, Bunsen burner, gauze and a spatula.
5.1What piece of essential apparatus has been missed in order for filtration to take place?(1)
5.2Where would you expect to find the salt, residue or filtrate?(1)
5.3If the aim of the experiment was to obtain a sample of dry salt, name a piece of apparatus that would be needed for the next step of the experiment in order to obtain the sugar? (1)
5.4What method would you use to separate two miscible liquids with different boiling points, which had been mixed together? (1)
5.5Name the apparatus you could use to measure out 23.5 cm3 of a liquid most accurately.(1)
[5]
QUESTION 6 MEASUREMENT
The label on a ream of A4 paper reads 75 g/m2, 500 sheets.
6.1If each sheet measures 8.3cmby 11.7 cm calculate the area of each sheet of A4 paper in cm2. (2)
6.2Convert this area to a measurement in m2. (1)
6.3Using information supplied in the label, calculate the mass of one sheet of paper in grams.(2)
6.4A friend tells you that the measurement 75 g/m2 represents the density of the paper, is he correct? (1)
[6]
QUESTION 7SOLUBILITY
The questions that follow refer to the solubility curves on the graph shown here.
7.1Write the formulae of the substance with the lowest solubility at 10oC. (1)
7.2What is the maximum mass of potassium chloride that will dissolve in 100 g water at 80oC? (1)
7.3If you needed to dissolve 80g of potassium nitrate into 100g of water what would the minimum temperature need to be? (1)
7.4If the maximum mass of ammonium chloride was dissolved in 100g of waterat 70oC and then the solution was allowed to cool to 50oC, what mass of ammonium chloride would crystallise?
(1)
7.5Suggest one way you could dissolve more than 10g of Ce2(SO4)3 in water at room temperature. (20o) (1)
[5]
QUESTION 8ELEMENTS, ATOMS & SYMBOLS
8.1Define an element.(2)
8.2State one property of a non-metal.(1)
8.3Give the name of the following compound: Na2O.(2)
[5]
QUESTION 9FORCE, WORK, ENERGY and POWER
9.1What energy change takes place when a rock falls off a high cliff?(2)
9.2A man pushes a car along a road with a force of 500N. If he does 10 000 J of work while pushing the car calculate the distance he pushed for. (3)
9.3A person with a mass of 65 kg is lifted 100 m vertically into the air by a hot air balloon.
9.3.1Calculate the work done by the balloon.(4)
9.3.2Calculate the power of the balloon if it takes 130 seconds for the balloon to rise up 100m. (3)
[12]
QUESTION 10HOOKE’S LAW
10.1Some science students conduct an investigation into Hooke’s law and record their results in the table below.
Load (N) / Length (m)0 / 0.33
10 / 0.45
15 / 0.51
20 / 0.57
25 / 0.63
30 / 0.75
10.1.1Calculate the extension of the spring when the load was 20N. (2)
10.1.2Use the extension you have just calculated, to find the constant of proportionality(k) for the spring. (3)
10.1.3One of the students says that the reading for the 30 N load is “wrong”. Use a calculation to support their claim. (2)
10.1.4What is the most likely reason for this error other than simply reading the length or load incorrectly. (1)
10.2Calculate what load would have been required to give an extension of 0.05 m.(3)
[11]
QUESTION 11LIGHT
11.1State two properties of the image formed in a pinhole camera.(2)
11.2State two ways you can enlarge the image formed in the pinhole camera.(2)
11.3Complete the diagram on your answer sheet showing how light is reflected off a plane mirror. Show clearly the angle of the reflected ray. (2)
11.4What do we know about the position of the reflected image in a mirror?(2)
11.5Explain why the word “AMBULANCE” is written backwards on the front of vehicles used as ambulances. (2)
[10]
QUESTION 12THERMAL EFFECTS
12.1What is heat?(2)
12.2Is the Ingenhaus apparatus is used to demonstrate conduction, convection or radiation?(1)
12.3Use particle theory to explain whether convection happens faster in gases or in liquids.(2)
12.4The picture represents a sheet of metal which has a circular hole cut through the middle of it. How would you expect the radius of the hole to change if the sheet of metal is heated? (1)
12.5Explain why people are advised to wear many layers of clothing in order to stay warm in cold weather? (2)
12.6Explain why a cement floor feels colder than a carpeted floor.(2)
[10]
END OF PAPER
GRADE 8 EXAMANSWER SHEET PHYSICAL SCIENCE
Name:______Teacher: DL KK GR KW PW KJW
(Circle)
For Examiners use ONLYQ1 / /34
Q2 / /6
Q3 / /5
Q4 / /11
Q5 / /5
Q6 / /6
Q7 / /5
Q8 / /5
Q9 / /12
Q10 / /11
Q11 / /10
Q12 / /10
TOTAL / /120
Marked by
SECTION A
Question 1 Multiple choice
Make an Xin the appropriate box (A – D)next
to the question number (1.1 – 1.17).
A / B / C / D1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
1.10
1.11
1.12
1.13
1.14
1.15
1.16
1.17
17 x (2) = [34]
Question 2: One-word answers.
Write only the appropriate word or term next to the question number 2.1 – 2.6
2.1(1)
2.2 (1)
2.3 (1)
2.4 (1)
2.5 (1)
2.6
(1)
6 x (1) = [6]
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