5.7.1 The Concept of Momentum (Structured Questions)


Question 1:
Diagram 1.1 and Diagram 1.2 show an experiment to study the collision between trolleys of different masses with a plasticine block.



Both trolleys move with the same velocity.
(a) State the variables in this experiment.
(i) Manipulated variable [1 mark]
(ii) Responding variable [1 mark]

(b)(i) What can you observe about the plasticine block after the collision? [1 mark]
(ii) State one inference that can be made based on the observation in (b)(i). [1 mark]

(c) State the hypothesis of this experiment. [1 mark]


Answer:
(a)(i)
Mass of the trolley

(a)(ii)
Depth of the dent on the plasticine block

(b)(i)

Trolley T produced a deeper dent on the plasticine block compared to the dent produced by trolley S after their collision with the plasticine block.

(b)(ii)

When a moving trolley with a bigger mass collides with a plasticine block, it produces a deeper dent on the plasticine block.

(c)
The bigger the mass of a moving trolley which collides with a plasticine block, the deeper the dent which will be formed on the plasticine block.


Question 2:
Diagram 2.1 shows an experiment to study the collision of a trolley with block M. After collision, block M is displaced to a new position.
The experiment is repeated using two trolleys as shown in Diagram 2.2.



The result of this experiment is shown in Table below.


(a) Measure the displacement of block M after the collision in Diagram 2.2.  [1 mark]

(b) State one observation about displacement of block M in diagram 2.1 and 2.2[1 mark]

(c) State the variables in this experiment.
(i) Constant variable [1 mark]
(ii) Manipulated variable [1 mark]

(d) Predict the displacement of block M if three trolleys are used. [1 mark]

Answer:
(a) 6 cm

(b)
The displacement of block M increases when the number of trolley increases.

(c)(i)
Length and slope of runway, mass of block M.

(c)(ii)
The number of trolley used

(d)
9 cm

4.7.6 Natural Polymers (Structured Questions)


Question 1:
Diagram 1.1 shows an experiment to study the effect of vinegar and ammonium solution on latex.
Diagram 1.2 shows the result of the experiment after 30 minutes.






(a) Write down one observation from the result of this experiment. [1 mark]

(b) State one inference based on the observation in Diagram 1.1. [1 mark]

(c) State one constant variable in this experiment. [1 mark]

(d) State one hypothesis for this experiment. [1 mark]

(e) Based on this experiment, state the operational definition for acid. [1 mark]


Answer
:
(a)
Vinegar causes the coagulation of latex but ammonia solution prevents the coagulation of latex.

(b)
When vinegar (an acid) is mixed with latex, the latex coagulates.
When ammonia solution (an alkali) is mixed with latex, the latex does not coagulate.
(any one)

(c)

1. 10 cm3 of latex
2. Results of the experiment are observed after 30 minutes
(any one)

(d)
Acid causes the coagulation of latex but alkali prevents the coagulation of latex.

(e)
Acid is a substance which causes latex to coagulate. 

4.7.4 The Oil Palm and Its Importance to National Development (Structured Questions)


Question 1:
Diagram 1.1 shows the process of latex coagulation.


(a)(i) State one example of chemical P? [1 mark]

(ii) State one characteristic of coagulated latex in Diagram 1.1. [1 mark]

(b) Chemical P in diagram 1.1 is replaced with chemical Q to prevent latex from coagulating.
State one example of chemical Q. [1 mark]


(c) Diagram 1.2 shows the process when natural rubber is heated with Sulphur to form rubber R.

  (i) Name process X. [1 mark]
  (ii) Name rubber R. [1 mark]

(d) Mark (\/) the object which is made of rubber R. [1 mark]




Answer:
(a)(i)
Methanoic acid

(a)(ii)
Elastic

(b)
Ammonia solution

(c)(i)
Vulcanization of rubber

(c)(ii)
Vulcanized rubber

(d)




4.7.2 Alcohol and Its Effects on Health (Structured Questions)


Question 1:
Diagram 1.1 and Diagram 1.2 show an experiment to investigate the effect of temperature on the fermentation of glucose by yeast.



(a) State one hypothesis that can be made from this experiment. [1 mark]

(b) State the variables in this experiment.
  (i) Manipulated variable [1 mark]
  (ii) Responding variable [1 mark]

(c) Based on Diagram 1.1 and 1.2, which temperature is more suitable for the fermentation of glucose? [1 mark]


(d) Diagram 1.3 shows the graph of the volume of carbon dioxide produced at 35oC against time.

What is the relationship between the volume of carbon dioxide produced and time? [1 mark]


Answer:
(a) Fermentation of glucose by yeast is affected by temperature.

(b)(i)
Temperature of the water bath

(b)(ii)
Volume of carbon dioxide produced

(c)
35oC

(d)
The volume of carbon dioxide produced is directly proportional to time. 


4.7.1 Various Carbon Compound (Structured Questions)


Question 1:
Diagram 1.1 shows two examples of carbon compounds, K and L.



(a)(i) Based on Diagram 1.1, which one is an inorganic carbon compound? [1 mark]

(ii) State one characteristic of an inorganic carbon compound. [1 mark]

(b)(i) State one use of compound K. [1 mark]

(ii) State one effect of compound K on the nervous system if consumed excessively. [1 mark]

(c) Diagram 1.2 shows a tank containing gas M used for gas stoves.
Gas is a hydrocarbon compound.

(i) State two elements present in gas M. [1 mark]
 
(ii) State one source of gas M. [1 mark]


Answer:
(a)(i) L or marble chips

(a)(ii)
Originates from non-living things or does not originates from living things

(b)(i)
Alcoholic drink

(b)(ii)
Disrupts nerve coordination or slows down the transmission of impulses

(c)(i)
1. Hydrogen
2. Carbon

(c)(ii)
Petroleum


5.4.3 Extraction of Metals from their Ores Using Coke


5.4.3 Extraction of Metals from their Ores Using Coke

1. In industries, metal ores which are less reactive than carbon are heated with carbon to obtain pure metal.
2. Pure metals which can be extracted using carbon are zinc, iron, tin and lead.

Extraction of Tin from its Ore


Extracting tin ore in a blast furnace
 
1. Tin ore exists naturally as cassiterite (or tin oxide).
2. Tin ore is washed with water to remove sand, clay and others impurities.
3. After that, tin ore is roasted to take away foreign matter such as carbon, sulphur and oil.
4. Lastly, the tin ore is mixed with carbon and limestone in the form of coal and is heated in a blast furnace at a high temperature.
5. The function of the limestone is to remove impurities.
6. Reduction reaction occurs during heating, carbon which is more reactive that tin removes oxygen from the tin oxide to produce pure tin and carbon dioxide.


7.
Pure tin flows out from the furnace into moulds to harden as tin ingots.
8. At the same time, the limestone (calcium carbonate) breaks down to form quicklime (calcium oxide) which reacts with impurities to form slag

3.4.1 The Effects of Environmental Pollution (Structured Questions)


Question 1:
Diagram 1.1 shows a type of an environmental pollution in an industrial area.


(a)(i) Based on Diagram 1.1, what is released by the factory? [1 mark]

(a)(ii) State the type of pollution based on the answer in (a)(i). [1 mark]

(b) State the effect of pollution shown in Diagram 1.1 on human being. [1 mark]

(c) Suggest one method to control the pollution shown in Diagram 1.1. [1 mark]


(d) Diagram 1.2 shows the effect of environmental pollution due to the heat trapped by gas P.

(i) Name gas P. [1 mark]
(ii) Name the phenomenon shown in Diagram 1.2. [1 mark]


Answer:
(a)(i)
Thick black smoke (soot)

(a)(ii) Air pollution

(b)
The acidic gases in the smoke irritate and corrode the respiratory passage (causing asthma and bronchitis)

(c)
Fit electrostatic precipitators on the chimneys to attract the soot to the inner wall of the chimneys.

(d)(i)
Carbon dioxide

(d)(ii)
Global warming/ Greenhouse effect


Question 2:
Diagram 2 shows the atmospheric layer around the Earth.


(a)(i) What is layer K? [1 mark]

(ii) State the importance of layer K. [1 mark]

(b)(i) Name the substance which can damage layer K. [1 mark]

(ii) Name one appliance that releases the substance in (b)(i). [1 mark]

(c) State two effects if layer K is damaged. [2 marks]


Answer:
(a)(i)
Ozone layer

(a)(ii)
Absorbs harmful ultraviolet rays in sunlight

(b)(i)
Chlorofluorocarbon (CFC)

(b)(ii)
Aerosol spray

(c)
1. Ultraviolet ray reaching the Earth can cause skin cancer and cataract
2. Ultraviolet ray lower our body’s immunity to diseases.


2.4.3 The Nitrogen Cycle and Its Importance (Structured Questions)


Question 1:
Diagram 1 shows part of nitrogen cycle.


(a) What is represented by W? [1 mark]

(b) Name bacteria X and bacteria Y. [2 marks]

(c) State one importance of the nitrogen cycle in Diagram 1.1. [1 mark]

(d) Bacteria X can be found in the root nodules of a plant as shown in Diagram 1.2.[1 mark]


Name the type of plant shown in Diagram 1.2.
(e) The nitrogen cycle consists of several processes.
In Table below, mark (\/) the process involved in the nitrogen cycle. [1 mark]




Answer:
(a)
Animal proteins

(b)

X: Nitrogen-fixing bacteria
Y: Nitrifying bacteria

(c)

1. Ensures that nitrogen and compounds of nitrogen are always present around us.
2. Maintains relatively steady levels of nitrogen and compounds of nitrogen around us.
(any one)

(d)
Leguminous plant, pea plant, beans (any one)

(e)


(Form 5) 1.9.2 Useful Microorganisms (Structured Questions)


Question 1:
Figure 1 shows the result of an experiment to study the effect of different concentrations of an antibiotic on bacteria growth.



(a) State one hypothesis for this experiment. [1 mark]

(b) State the variables in this experiment.
(i) Manipulated variable [1 mark]
(ii) Responding variable [1 mark]

(c) Write down one observation for this experiment. [1 mark]

(d) What is meant by antibiotic based on this experiment (operational definition). [1 mark]


Answer:
(a)
A higher concentration of an antibiotic will kill more bacteria.

(b)(i)
Concentration of an antibiotic.

(b)(ii)
Clear area

(c)
The clear area that surrounds the antibiotic disc of high concentration is larger/ wider than the clear area that surrounds the antibiotic disc of low concentration.

(d)
Antibiotic is a substance that produces a clear area around the nutrient agar that contains bacteria.

(Form 5) 1.9.1 Factors that Affect the Growth of Microorganisms (Structured Questions)


Question 1:
Diagram 1 shows an experiment to study the effect of temperature on the growth of bacteria.



After 2 days, the appearance of the nutrient broth in each test tube is observed. The result recorded is shown in Table below.


(a) State the variables in this experiment.
(i) Manipulated variable [1 mark]
(ii) Responding variable [1 mark]


(b) State the hypothesis for this experiment[1 mark]

(c) State the inference that can be made based on this experiment. [1 mark]

(d) Based on this experiment, state the operational definition for bacteria. [1 mark]


Answer:
(a)(i) Temperature

(a)(ii)
Growth of bacteria

(b)
A suitable temperature is essential for the growth of bacteria.

(c)
Bacteria growth very fast at 37oC

(d)
Bacteria are tiny living organisms which grow and reproduce themselves under a suitable temperature.