2018 PSLE Science Examination Paper Analysis

In this article, we will be analysing the 2018 PSLE Science Examination Paper. We will be sharing the topic weightage for 2018 PSLE paper as well as discussing 2 interesting questions from the booklet B of this paper.

Table 1: Summary of Booklet A Analysis

Topics

Marks Allocated

Level

Theme

Question number

Reproduction in Plants

6

P5/6

Cycles

7, 9, 11

Man’s Impact on his Environment

5

P5/6

Interactions

5, 8, 10

Diversity of Living Things

4

P3/4

Diversity

1, 2

Diversity of Materials

4

P3/4

Diversity

18, 22

Water and Changes of State

4

P5/6

Cycles

20, 25

Using Electricity

4

P5/6

Systems

21

Forces

4

P5/6

Interactions

15, 26

Air and the Respiratory System

3

P5/6

Systems

3, 6, 14

Matter

2

P3/4

Cycles

19

Human Body Systems

2

P3/4

Systems

12

The Unit of Life

2

P5/6

Systems

13

Light and Shadows

2

P3/4

Energy

24

Heat and Temperature

2

P3/4

Energy

16

Energy in Food

2

P5/6

Energy

3, 14

Forms and Uses of Energy

2

P5/6

Energy

17, 28

Magnets and their Characteristics

2

P3/4

Interactions

23

Making Magnets

2

P3/4

Interactions

27

Living Together

2

P5/6

Interactions

4, 10

The Circulatory System

1

P5/6

Systems

6

Food Chains and Food Webs

1

P5/6

Interactions

4

Table 2: Summary of Booklet B Analysis

Topics

Marks allocated

Level

Theme

Question number

Heat and Temperature

6

P3/4

Energy

31(b), 36, 39(c)

Life Cycle of Animals

5

P3/4

Cycles

33

Reproduction in Plants

5

P5/6

Cycles

32, 34(a)

Adaptations

5

P5/6

Interactions

29, 30(a) (c)

Electrical Systems

4

P5/6

Systems

37(a), 38(a)

Forms and Uses of Energy

4

P5/6

Energy

35

Forces

4

P5/6

Interactions

37(b), 40(b)

Water and Changes of State

3

P5/6

Cycles

39(a) (b)

Living Together

3

P5/6

Interactions

30(b), 34(c)

Making Magnets

2

P3/4

Interactions

40(a) (b)

Plant Transport System

1

P5/6

Systems

34(b)

Using Electricity

1

P5/6

Systems

38(b)

Energy in Food

1

P5/6

Energy

31(a)

We have also identified the top 10 topics in 2018 PSLE Science Paper and most of the topics are taught in Upper Primary (Energy and Interactions). Hence it is very important that your child has a firm grasp of the concepts of these topics. Reproduction in plants has the highest weightage in the paper with 11 marks in total. This is an important topic in Primary 5 and requires the student to remember a lot of content about the plant reproduction processes. Reproduction in plants has been appearing as a highly-weighted topic for past 5 years in PSLE. Thus it is crucial for your child to be well-versed in this topic.

Other than Reproduction in plants, the other 2 topics that students should pay attention to are Heat Energy and Forces. Students tend to neglect revising well for Heat Energy as it is a P4 topic. However, concepts about Heat Energy are often tested in PSLE.

Table 3: Top 10 topics in 2018 PSLE Science Examination Paper

Topics

Total weightage by marks (%)

Level

Theme

Reproduction in Plants

11

P5/6

Cycles

Heat and Temperature

8

P3/4

Energy

Forces

8

P5/6

Interactions

Water and Changes of State

7

P5/6

Cycles

Forms and Uses of Energy

6

P5/6

Energy

Life Cycle of Animals

5

P3/4

Cycles

Adaptations

5

P5/6

Interactions

Living Together

5

P5/6

Interactions

Using Electricity

5

P5/6

Systems

Electrical Systems

4

P5/6

Systems

As shown in Table 3, this paper focuses on these topics Reproduction in Plants, Heat and Temperature, and Forces.  The topic on Electricity is also of high weightage, giving a total of 9 marks (“Using Electricity” and “Electrical System” combined). Hence, this paper is ideal for your child to practise on these topics.

Question Analysis

Most of the open-ended questions on Reproduction in Plants are direct and requires little answering technique, hence we would discuss Question 35 and Question 39 instead. From which we can learn the tips and answering techniques that are useful for answering questions on Forms and Uses of Energy, Heat and Temperature and Water and Changes of State, which many students tend to struggle with.

The discussion of the questions below will include
1) the recommended answers,
2) explanation of the answers,
3) comments on the answers and
4) tips or answering techniques for the question.


PSLE / 2018 / Q35

Peter has a toy train that runs on batteries. He placed plates of food on the train as shown below.

(a) When he switched on the toy train, it moved along the track. Fill in the boxes below to show the energy conversion as they train is moving. [2]

Answer:    Battery                Wires                     Train

Explanation: Batteries contains chemicals in which energy can be stored. Wires has electric current flowing through it from the battery to the toy train. Since the toy train moves, kinetic energy is possessed by it. Friction is present between the wheels and the track during the movement will be converted to heat energy and sound energy.

Comments: PSLE accepts “Potential energy” and students need not give “Chemical potential energy”.

Tips: Always put the main form of energy possessed by the object first e.g. “Kinetic energy”, then “Heat/sound energy”

(b) Peter did not change the batteries. Give a reason why the train moved faster as the food was removed. [1]

Answer: When the food was removed the train became lighter and hence, less electrical energy was converted into heat and sound due to friction and more electrical energy was converted into kinetic energy for the train to move faster.

Explanation: The greater the kinetic energy the train possesses, the faster the train moves.

Comments: PSLE requires specific references of the object, which the energy conversion is happening at, were missed out from the answer. It is better to write: “less electrical energy of the battery was converted into heat and sound energy of the train”, “more electrical energy of the battery was converted into more kinetic energy of the train for the train to move faster.

Tips: Use comparison words such as “lighter”, “less”, “more” to describe the difference in effects. Use keywords like “converted into” and add references to the energy forms (as mentioned in the comments).

(c) Peter placed a wooden block under the track at point H.

Explain why the train moved more slowly as it moved from G to H. [1]

Answer: Some electrical energy was converted into gravitational potential energy and hence, less electrical energy was converted into kinetic energy and the train moved more slowly.

Explanation: H is positioned higher than G, hence there is more gravitational potential energy at H than at G.

Comments: Again, PSLE requires specific references of the object, which the  energy conversion is happening at, were missed out from the answer. It is better to write: “Some electrical energy of the battery was converted into gravitational potential energy of the train, less electrical energy of the battery was converted into kinetic energy of the train ”.

Tips: Use comparison words such as “less”. Use keywords like “converted into” and add references of objects to the energy forms (as mentioned in the comments).


PSLE / 2018 / Q39

A worker used a truck to deliver blocks of ice. A mist was seen when ice was taken out of the truck as shown.

 

(a) Explain how the mist was formed. [2]

Answer: The water vapour in the surrounding air lost heat to the cooler air that came out of the truck when the ice was taken out. The cooled water vapour condensed and formed fine water droplets as mist.

Explanation: Heat travels from a region of higher temperature to a region of lower temperature. When a gas (water vapour) loses sufficient heat to the surroundings, it condenses into a liquid (water droplets).

Comments: PSLE requires the specific reference of where the water vapour is from – “in the surrounding air”, and where the heat is lost to – “the cooler air”.

Tips: Use keywords like “water vapour”, “ lost heat”,  “condensed” and “water droplets”.

(b) The mist disappeared after a short time. Explain why.  [1]

Answer: The mist took in heat from the warmer surroundings and evaporated to form colourless water vapour.

Explanation: Mist forms when the water vapour loses heat and condenses into fine water droplets, which then gain heat and evaporate.

Comments: PSLE requires the specific reference of where the heat is gained from – “from the warmer surroundings”.

Tips: Use keywords like “gains heat”, “evaporated” and “water vapour”. The answer must link back to the question of why the mist disappeared – “colourless water vapour”.

(c) Thick plastic strips were hung at the door to prevent the ice inside the truck from melting. Explain why. [1]

Answer: The plastic strips helped to keep the cold air inside the truck and prevented warmer air from the surroundings from entering the truck. Hence, the heat flow from the warmer surroundings to the ice to cause it to melt was reduced.

Explanation: Ice melts as it gains heat from its surroundings. When the heat gained by the ice is reduced, the melting of ice is reduced.

Comments: PSLE requires the direction of the heat flow to be specified –“from the warmer surroundings to the ice” and to mention that heat is gained by the ice. It is better to write: “The plastic strips helped to keep the cold air inside the truck and prevented the warmer air from the surroundings from entering the truck. Hence, the heat flow from the warmer surroundings to the ice was reduced, allowing the ice to gain less heat and cause it to melt slower.”

Tips: Melting suggests that the question is testing on the topics: “Heat and Temperature”, and “Water and Changes of States”. Hence, the answer would require the keyword “gain heat” and use comparison words such as “less” and “slower” to show the change due to the thick plastic strips.


Hope this article benefits your children in writing more accurate and complete answers for the PSLE science questions and that he/she would score better in the examinations. Stay tune for 2019 Examination Paper Analysis!

Like what you see?

Register for a trial class and see what more we can provide for your child today!

Recent Articles

Secondary Blog

Secondary Blog

Resources & Topics Overview