sample peka sains spm (3)
TRANSCRIPT
SAMPLE EVIDENCE 1
Topic : Effect of impurities on the boiling point of a pure liquidAim To study the effect of impurities on the boiling point of distilled
water
Hypothesis The present of salt increases the boiling point of distilled water
Variables(a) Constant Volume/Amount/Quantity of distilled water(b) Manipulated The Presence of salt (c) Responding Boiling point of distilled water
Material/Apparatus Distilled water, salt, 100 cm3 beaker, wire gauze, tripod stand, Bunsen burner, thermometer
Procedure
1. Distilled water is poured into a beaker until it is half full.2. The water is heated until it boils. The temperature when the water boils (boiling temperature) is recorded3. Two spatulas of salt are added into the distilled water and the mixture is heated again.4. The temperature of the boiling mixture of water and salt is recorded.
Results
The Presence of salt Boiling point of distilled water (oC)
Absent 100
Present 102
Discussion Without impurities the boiling point of distilled water is 100 oC but with the presence of impurities, the boiling point of water is increased. The boiling point of distilled water is increased with the presence of impurities.
Hypothesis is accepted
Conclusion The presence of impurities increases the boiling point of distilled water.
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Distilled water
Heat
Thermometer
Beaker
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C1 P2
C1 P3
Note: All variables must be correct
C1 P4
C1 P5C3 P1
C3 P2
C3 P3
C4 P1
C4 P2
C4 P3
SAMPLE EVIDENCE 2
Topic : Variation
Aim
Hypothesis
Variables Constant : Manipulated : Responding :
Apparatus and Materials:
Procedure :
Result:
Discussion:
Conclusion.
To study the variation of leaves.
Different leaves have different lengths.
Type of plant ( species of plant)Number of leaves Length of leaves
Leaves, ruler
1. 10 leaves from the same plants are collected by the students. 2. The length of a leaf is measured.3. The length of leaves is recorded in the table.4. The experiment is repeated with another leaf.
Number of leaves Length of leaves (cm)1 4.32 5.23 4.14 5.75 5.56 4.47 6.48 6.29 5.3
10 4.5
Variations in the length of the leaves show normal distribution. There is a whole range of intermediates between the shortest and the longest.
Hypothesis is accepted.
Different leaves have different lengths //The length of the leaves show continuous variation
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Length of leaves /cm
Length of leaf
Metre rule
Leaf
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C1 P2
C1 P3
C1 P4
C1 P5
Note: All variables must be correct
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C3 P2
C3 P3
C4P1
C4P2
C4P3
SAMPLE EVIDENCE 3
Topic : Exothermic and endothermic reactions
Aim To study exothermic and endothermic reactions.
Hypothesis Different types of chemical cause different changes in temperature in the reaction with water.
Variables(a) Manipulated Types of chemical(b) Responding Increase or decrease in temperature(c) Constant Volume of water / quantity of chemical substances
Material/Apparatus Sodium hydroxide crystals, ammonium chloride powder, distilled water, test tube, thermometer , spatula
Procedure
1. 5cm3 of distilled water is poured into a test tube.2. The initial temperature of distilled water is recorded.3. 1 spatula of sodium hydroxide pellet is added into the test tube.4. The mixture is stirred until the sodium hydroxide dissolved.5. Then the final temperature is recorded in the table.6. The experiment is repeated by using ammonium chloride powder.
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Thermometer
Distilled water
Ammonium chloridepowder
Sodium hydroxide pellet
C1P1
C1P2
C1P3
Note: All variables must be correct
C1P4
C1P5
ResultsTypes of chemicals
Initial temperature of substance (oC)
Final temperature of substance (oC)
Change in temperature (0C)
Sodium hydroxide crystals and distilled water
29.0 60.0 31.0
Ammonium chloride powder with distilled water.
29.0 15.0
-14.0
Discussion An exothermic reaction occurs when temperature increases because heat is released to the surrounding.An endothermic reaction occurs when temperature decreases because heat is absorbed from the surrounding.
Hypothesis is accepted.
Conclusion 1. An exothermic reaction is a chemical reaction that involves an increase in temperature.
2. An endothermic reaction is a chemical reaction that involves a decrease in temperature.
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C3P1
C3P2
C3P3
C4P1
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C4P3
SAMPLE EVIDENCE 4
Topic: Focal length of a convex lens.
Aim
Hypothesis
Variables Constant : Manipulated : Responding :
Apparatus and Materials:
Procedure :
Result:
Discussion:
Conclusion:
To study the focal length of a convex lens.
The thicker the lens, the shorter the focal length.
Type of lens.Thickness of the lensFocal length
Convex lens, lens holder, metre rule, screen.
1. The apparatus is set up as shown in the diagram.2. The lens is directed at a distant object3. The screen is adjusted until a sharp image forms on the
screen.4. The distance between the lens and the screen is measured5. The experiment is repeated using another convex lens with a
different thickness.
Thickness of the lens Focal length(cm)Thin 25
Moderate 20Thick 15
The focal length of a convex lens depends on the thickness of the lens. A thin convex lens has a longer focal length. A thick convex lens has a shorter focal length. Hypothesis is accepted.
The thicker the lens, the shorter the focal length.
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Rays from distance object
Convex lens screen
C1 P1
C1 P2
Note: All variables must be correct
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C4 P3
C4 P2
C4 P1
C3 P3
C1 P5
C1 P4
C1 P3
C3 P2
focal length
SAMPLE EVIDENCE 5
Topic : Resistance of alloy to corrosion.
Aim To investigate the properties of alloy and pure metal
Hypothesis Alloy is more resistance to rust than pure metal.
Variables(a) Manipulated Type of nail(b) Responding Rate of rusting (c) Constant Distilled water, temperature , time
Material/Apparatus Steel nail, pure iron nail, distilled water, test tubes , test tube rack
Procedure
1. Test tubes A and B are prepared.2. 5cm3 of distilled water is poured into test tubes A and B. 3. A steel nail is put into test tube A and an iron nail is put into
test tube B and both test tubes are kept at room temperature for 2 days.
4. After 2 days the condition of the nails are observed and recorded in the table below.
ResultsTypes of nail Presence of rust
Steel nailNo rust
Iron nail Rust
Discussion The steel nail in test tube A is more resistant to rusting than the iron nail in test tube B.Hypothesis is accepted.
Conclusion Steel nail is more resistant to rust than iron nail.
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Test tube A Test tube B
Distilled water
Steel nail Iron nail
C1 P1
C1 P2
C1 P3
Note: All variables must be correct
C1 P4
C1 P5C3 P1
C3 P2
C3 P3
C4 P1
C4 P2
C4 P3
SAMPLE EVIDENCE 7
Topic: The effect of humidity on the growth of microorganisms
Aim : To study the effect of humidity on the growth of microorganisms
Hypothesis : Microorganisms grow rapidly in moist condition
Variables : Constant : Type of bread/ temperature/ nutrient content Manipulated : Presence of moisture/ water Responding :The growth of microorganisms /mucor/fungi
Materials/Apparatus : 2 pieces of bread, water, clear plastic bag.
Procedure : 1. A piece of bread is sprinkled with water and placed in a clear plastic bag labeled A.
2. The other piece is kept dry and placed in the clear plastic bag labeled B.
3. Both plastic bags are kept in a dark cupboard for two days.4. The result of the experiment is observed and recorded in
the table below.
Results :Presence of moisture The growth of mucorA Moist bread Yes / A lot of mucorB Dry bread No / A few mucor
Data interpretation and discussion
: After two days the mucor grows on the moist bread because of the presence of water but no mucor grows on the dry bread. Mucor needs water to grow. Hypothesis is accepted.
Conclusion : Microorganisms grow rapidly in moist condition
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B: Dry bread A: Moist bread
Plastic bag
C1 P1
C1 P2
C1 P3Note: All variables must be correct
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C1 P5C3 P1
C3 P2
C3 P3
C4 P1
C4 P2
C4 P3
SAMPLE EVIDENCE 8
Topic : The effect of pH on the growth of microorganisms
Aim : To study the relationship between pH value and the growth of microorganisms
Hypothesis : Bacteria thrives in neutral conditions / neutral condition is suitable for the growth of microorganisms
Variables : Constant variable : Volume of nutrient broth Manipulated variable : pH value Responding variable : Cloudiness of the nutrient broth
Materials/ : Sterile nutrient broth, bacteria culture (Bacillus subtilus), distilled water,apparatus hydrochloric acid 1 mol/dm , sodium hydroxide solution 1 mol/dm3 ,
test tubes,cotton wool.
Procedure 1. Three test tubes labeled A,B and C are prepared.2. 5 cm3 of nutrient broth is poured into each test tubes3. 1 cm3 of bacteria culture is added into each test tubes.4. 1cm3 of hydrochloric acid, 1cm3 of sodium hydroxide solution and
1cm3 of distilled water are added by using syringes into the nutrient broth in test tubes A ,B and C respectively.
5. The test tubes A, B and C are plugged with cotton wool6. The three test tubes are kept in the dark cupboard for 2 days.7. The content of the test tubes are observed and recorded.
Observation
Test tubes Condition of the
nutrient agarCloudiness of the
nutrient brothA Acidic Slightly cloudyB Alkaline Slightly cloudyC Neutral Very cloudy
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Nutrient broth + bacteria culture
A B C Acidic Alkaline Neutral (Hydrochloride acid) ( Sodium hydroxide solution) (Distilled water )
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C1 P2
C1 P3
Note: All variables must be correct
C1 P4
C1 P5
C3 P3C3 P2
C3 P1
C3 P3C3 P2
Discussion
After two days , nutrient broth in test tubes A and B becomes only slightly cloudy because microorganisms do not grow well in acidic and alkaline conditions. In test tube C, the nutrient broth becomes very cloudy because microorganisms grow rapidly in neutral condition..
Hypothesis is accepted Conclusion: . Bacteria grows rapidly in neutral condition/ neutral condition is the most suitable pH for the growth of microorganisms.
SAMPLE EVIDENCE 9Topic : PressureAim To study the relationship between weight (force) and depth of
immersion of weight (pressure)
Hypothesis The bigger the mass the deeper the immersion of weight.// The bigger the force the higher the pressure
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C4 P2
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C1 P1
C1 P2
Variables1. manipulated2. responding 3. constant
The mass of weightDepth of immersionSurface area of weight
Materials/Apparatus Flour, 100 g weight, 200 g weight, 300 g weight, retort stand, clamp, container ,metre rule, thread, pair of scissors.
Procedure
1. The apparatus as shown in Diagram 1 is prepared.2. The threat is cut with a pair of scissors and the weight is
let to fall into the flour in the container.3. The depth of immersion of the weight into the flour is
marked on the weight or weight rod as shown in Diagram 2.
4. The depth of immersion is measured and recorded in table below.
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Diagram 2
depth of immersion
mark
flour
flour
container
thread
40 cm
20 cm
retort stand
Weight100 g
weight rod
Diagram 1
Note: All variables must be correct
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C1 P4
5. Steps 1 to 4 are repeated with 200g and 300g weights.
Observation
Mass of weight (g) 100 200 300Depth of immersion (cm) 2 3
4
Discussion The bigger the mass of weight, the bigger the force and pressure produced. A higher pressure causes a deeper immersion.
Hypothesis is accepted.
Conclusion The bigger the force the higher the pressure.
SAMPLE EVIDENCE 10
Topic : Inertia
Aim To investigate the relationship between mass and inertia.
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C1 P5
C3 P1
C3 P2
C3 P3
C4 P1
C4 P2
C4 P3
C1 P1
Hypothesis The larger the mass of an object ,the greater the inertia of the object.
Variables(a) Manipulated The mass of sphere(b) Responding The distance of the sphere’s movement(c) Constant The angle of inclination , the length of thread,
the mass of pendulum
Material/Apparatus Thread, mass of spheres of 50g, 100g,150g , retort stand , pendulum and metre rule.
Procedure
1. The apparatus is set up as shown in the diagram above. 2. The pendulum with 50g weight is tied to the retort stand with a 50cm length of thread.3. The pendulum is displaced at an angle of inclination of 30º
from the perpendicular and released to knock the 50g sphere on the table.
4. The distance of the sphere’s movement is measured with a metre rule.5. The result is recorded in the table below.6. Steps 1- 5 are repeated by using 100g and 150g mass of sphere.
ResultsMass of sphere/g
Distance of sphere’s movement/cm
50 60
12
30O
ThreadPendulum
Sphere
Retort stand
Table
C1 P2
C1 P3
C1 P4
C1 P5
C3 P1
C3 P2
100 45150 25
Discussion When the mass of the sphere increases the distance of the sphere’s movement decreases. The greater the mass of an object, the greater the inertia.The greater the mass the more the object tends to remain at rest and resist a change in motion.
Hypothesis is accepted.
Conclusion The greater the mass of an object the greater the inertia produced
SAMPLE EVIDENCE 11
Topic : Proprioceptor
Aim : To observe the role of proprioceptors in arrange cans in the correct order without looking
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C3 P3
C4 P1
C4 P2
C4 P3
C1P1
Hypothesis :. Proprioceptors helps us to arrange cans in the correct order without looking
Variables : manipulated variable : Number of students responding variable : Ability to arrange cans in the correct order fixed variable : Mass of cans
Apparatus : sand, five copper can of equal size
Procedures : 1. This activity must be done in groups 2. All the five cans must be filled with sand of different weights for example:
Can One Two Three Four Five
Weight of sand 50 g 100 g 150 g 200 g 250 g
3. One of my friend is asked to close his eyes4. His eyes are covered with a piece of cloth.5. The five cans are arranged randomly in front of my friend whose eyes
have been covered.6. He is asked to pick up the cans one by one and arrange the cans
according to their weight either in descending and ascending order.7. Role among group members are exchanged and the step above are
repeated.8. The observations are recorded in the table.
ResultNumber of
Student Ability to arrange in the correct order (Yes /No)
1 Yes
2 Yes
3 Yes
4 Yes
5 Yes
Discussion : Proprioceptors are receptor in our body that sense the position of our body that sense the position of our body
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C1P3
C1P4
Note: All variables must be correct
C1P5
C3P1
C3P2
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We can arrange can without looking because our body has proprioceptorsProprioceptors are important because the enable us to be concious of the position and the posture of our body.The receptor in the muscle related to proprioceptore is called stretch receptor.The other function of proprioceptors also enables us to detect the movement of our body without looking.
Hypothesis is accepted
Conclusion : Proprioceptors are receptor that enable us to be conciousabout the movement of our body parts as well as its functions without using our eyesight
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C4P1
C4P2
C4P3