WELLINGTON PRIMARY SCHOOL
Science Workshop for Parents
23 May 2014
Programme Overview
1.Common Misconception
2.Answering using keywords
3.Hands-on
4.Q & A
TOPIC: LIVING THINGS (P3)
× Overcrowding leads to shorter plants.
SCIENTIFIC CONCEPT:
Overcrowding leads to competition for
sunlight. Plants will try to grow as tall as
possible to obtain as much light,
leading to taller plants, not shorter.
TOPIC: MAGNETS (P3)
× All metals are magnetic.
SCIENTIFIC CONCEPT:
Only some metals like iron, steel, nickel
and cobalt are magnetic.
TOPIC: BODY SYSTEMS (P3)
× Digestion takes places in the stomach and
small intestine only.
SCIENTIFIC CONCEPT:
Saliva in the mouth contains digestive
enzymes that will break down the food.
Digestion takes places in the mouth, stomach
and small intestine.
.
TOPIC: MAGNETS (P3)
× As long as 1 end of the object is attracted by a magnet,
it can be concluded that the object is a magnet.
SCIENTIFIC CONCEPT:
By testing for attraction on just 1 end of the object, the
object could either be a magnetic material or magnet. To
conclude that it is a magnet, one end must attract and the
other end must repel the magnet.
TOPIC: LIFE CYCLE OF PLANTS (P4)
× Germination requires sunlight.
SCIENTIFIC CONCEPT:
Only air, water and warmth are needed for
germination. Light is not necessary at this
stage. Light is only necessary when plants
start to have leaves to photosynthesize.
TOPIC: STATES OF MATTER (P4)
Two properties of air are:
i)They do not have a definite volume.
ii)They can be compressed. ×
SCIENTIFIC CONCEPT:
Two properties of air are:
i)They do not have a definite volume and so
they can be compressed.
ii)They do not have a definite shape.
TOPIC: LIGHT (P4)
× We can see things because our eyes give
out/ off light.
SCIENTIFIC CONCEPT:
We can see luminous objects e.g. sun,
because they give out light that enters our
eyes.
We can see non-luminous objects because
they reflect light from the light source.
TOPIC: HEAT (P4)
× Temperature is the same as heat.
SCIENTIFIC CONCEPT:
Temperature is the degree of hotness.
Heat is the quantity of hotness, a form of
energy.
e.g. In melting of ice cubes, heat is gained
but temperature remains the same at 0’C.
TOPIC: HEAT (P4)
× An object becomes hotter because it
has lost its coldness.
SCIENTIFIC CONCEPT:
An object becomes hotter because it
has gained heat from a heat source.
Heat travels from a hotter place to a
colder place.
TOPIC: HEAT (P4)
× A white object is less hot than a black
object because it reflects more heat.
SCIENTIFIC CONCEPT:
Light is reflected. So when more light is
reflected off the white object, it is less
hot than the black object.
TOPIC: WATER CYCLE (P5)
× We can see steam rising from a bowl
of piping hot soup.
SCIENTIFIC CONCEPT:
Steam cannot be seen. The mist we
see is actually condensed steam / tiny
water droplets.
TOPIC: WATER CYCLE (P5)
× Water vapour evaporates from the
cup of water.
SCIENTIFIC CONCEPT:
Only water evaporates (liquid to
gaseous). Water vapour can only
condense (gaseous  liquid).
TOPIC: WATER CYCLE (P5)
× Clouds are made up of water vapour.
SCIENTIFIC CONCEPT:
Clouds are made up of many water
droplets gathered together.
They are prevented from falling by air
resistance. They will fall as rain/ snow
when they are heavy enough.
TOPIC: CELLS (P5)
× All plant cells contain cell wall and chloroplasts.
SCIENTIFIC CONCEPT:
Most plant cells contain chloroplasts to trap light
to make food. However, chloroplast are not found
in onion skin cells though they are also plant
cells. They do not need chloroplasts as they are
found underground where no sunlight can reach.
TOPIC: ENERGY / FORCE (P5/6)
× A coconut on a tall tree has high gravitational
force.
SCIENTIFIC CONCEPT:
A coconut on a tall tree has high gravitational
potential energy.
Gravitational Force = Gravity
Gravitational Force ≠ Gravitational Potential Energy
TOPIC: FORCE (P6)
× Mass and weight are the same and they are equal at
all times.
SCIENTIFIC CONCEPT:
Mass ≠ Weight
Mass = amount of matter that makes up the object
Weight = measure of the gravitational force / force of
gravity acting on the object
On Earth,
Mass of boy = 42 kg
Weight of boy = 42 kg
On Moon
Mass of boy = 42 kg
Weight of boy = 7 kg
TOPIC: FORCE (P6)
× The weight of the object does not depend on
its mass.
SCIENTIFIC CONCEPT:
The greater the mass of an object, the greater
the weight of an object on Earth.
Weight = measure of the gravitational force /
force of gravity acting on the object
Gravity is dependent on the mass.
TOPIC: FORCE (P6)
× There is no friction between 2 smooth
surfaces.
SCIENTIFIC CONCEPT:
There is less friction. Even the
smoothest surface will have friction.
•They are not specific in their explanation.
•They fail to use the key scientific terms,
E.g. Matter occupies space.
The metal rod is a better conductor of heat
than the plastic rod, hence it gains heat
faster.
Disclaimer: All answers given here are solely for the
purpose of explaining the given questions in this
workshop. These answers are collated by the
department teachers based on our Science teaching
experience and are in no way endorsed by MOE as
the only approved way of answering. Explanations
may differ in similar questions due to different mark
allocation and question focus etc.
Look at the diagrams below.
Write down 1 observation after the stone enters the
measuring cylinder. (1m)
Qn: Write down an observation when the stone enters
the measuring cylinder. (1m)
Key Concept(s) covered: Properties of Matter
Student’s Answer: The water increased. (0m)
Teacher’s Answer:
The water level that increased. (1m)
(Note: Pupils must be precise in their answering.)
Trisha wants to find out which Material X, Y or Z is the
best conductor of heat. She prepares her setup as shown
below.
Trisha placed the beakers on the same table in the
kitchen. She then took the temperature of the water
every 5 minutes for 30 minutes. She presented her
findings in a table below:
Time Interval
Temperature of water recorded at different
intervals
Material X
Material Y
Material Z
0 min
90
90
90
5 min
88
80
75
10 min
86
72
69
15 min
83
64
54
20 min
80
53
44
Qn: Trisha wishes to make a pouch for her water bottle to keep
her drinks cold for the longest possible time.
Which is the best material for the pouch? Explain your answer.
(2m)
Key Concept(s) covered: Properties of materials, Heat conduction
Student’s Answer: Material X. It is a poor conductor of heat. ( 0m)
Teacher’s Answer: Material X. After 20 minutes, the drink
remains the warmest (0.5m) in beaker made of Material X. So it is
the poorest conductor of heat (1m) amongst the 3 materials to
conduct heat from the surrounding air to Trisha’s cold drink
(0.5m).
(Note: Pupil did not use data provided to support his answer. There
must also be use of superlative adjectives in comparison
questions.)
Siti placed a cork and stuck it gently at the mouth of an empty glass
flask. Then she placed a lighted candle at the base of the flask as
shown below.
Qn: Based on the information above, what would Siti
observe of the cork after some time? Explain your
answer. (2m)
Key Concept(s) covered: Heat gain, Expansion
Student’s Answer: The cork shoots out (0.5m) because
the air pushes it out (0.5m).
Teacher’s Answer: The cork shoots out (0.5m) because
the air inside the flask gains heat (0.5m) and expands
(0.5m), then pushes it out (0.5m).
(Note: Pupil did not explain what caused the push.)
Rozi conducted an experiment using a torch, a wooden cube and a white
screen. Her set-up is shown in the diagram below.
She then changed the distance between the torch and the wooden cube to find
out its effects on the shadow formed on the screen. Her findings are then
recorded in the table shown below.
Distance X (cm)
Height of the shadow formed on the screen (cm)
10
30
20
24
30
18
40
12
Qn: Based on the table given, what is the relationship
between Distance X and the height of the shadow formed
on the screen? (1m)
Key Concept(s) covered: Light, Shadow size
Student’s Answer: The height of the shadow decreases. (0m)
Teacher’s Answer: The greater the Distance X, the shorter
the height of the shadow (1m) formed on the screen.
(Note: Pupil did not explain use the question wording provided.
There is no relationship established between the variables
mentioned)
Mrs Sim wanted to find out if the type of soil affects the
growth of a plant. She prepared 2 similar pots of plants as
shown below. She watered them daily and placed them
beside the window.
Qn: State two other variables which Mrs Sim needed to
keep the same to conduct a fair test for her experiment.
Key Concept(s) covered: Constant variables
Student’s Answer:
1)The water (0m)
2)The soil (0m)/ the type of soil (0m)
Teacher’s Answer:
1)The amount of water (1m)
2)The amount of soil (1m)
(Note: Pupil did not specify what he meant by “soil”, the
amount of soil? The colour of the soil?)
Disclaimer: All answers given here are solely for the
purpose of explaining the given questions in this
workshop. These answers are collated by the
department teachers based on our Science teaching
experience and are in no way endorsed by MOE as
the only approved way of answering. Explanations
may differ in similar questions due to different mark
allocation and question focus etc.
Mark carried out an experiment on an organism A.
He cuts it at the centre into 2 parts with the top part
consisting of the cap and the bottom consisting of
the nucleus.
Qn: What is the aim of the experiment?
Key Concept(s) covered: The function of a part of a cell.
Student’s Answer: The nucleus controls the activities
of the cell. (0m)
Teacher’s Answer: To find out if nucleus is required
(1m) for the repair of any cuts to the organism(1m).
(Note: Pupils must answer with reference to the
question and not just write a general statement.)
Josh set up an experiment as shown below.
The set-ups, A and B, are placed in a tightly locked
cupboard for two days.
After two days, he observed that the limewater in dish A
had turned milky but the limewater in dish B remained
clear.
Qn: Why do you think set-up B was included in the
experiment?
Key Concept(s) covered: Plant Transport System –
Generating Variables in an experiment.
Student’s Answer: It is to act as a control. (0 m)
Teacher’s Answer: Set-up B acts as a control to ensure
that the carbon dioxide produced comes from the potted
plant and not the air in the bottle (1m).
(Note: Incomplete explanation of “control”.)
Sue left a glass of water with some ice cubes on the table.
After a while, she noticed water droplets on the outer
surface of the beaker.
Water droplets
Qn: Explain how the water droplets on the outer surface
of the glass were formed.
Key Concept(s) covered: Water Cycle.
Student’s Answer: By condensation. (0.5m)
Teacher’s Answer: Water vapour (0.5m) in the surrounding
air lost heat (0.5 m) and condensed(0.5m) when it comes
into contact with the cooler surface (0.5m) of the glass.
(Note: Pupil did not explain the process but merely stated
what happened.)
Study the diagram of a circuit of an alarm shown below carefully.
In the above set-up, when the switch was closed, the striker was
observed to be pulled back towards the rod (as represented by the
dotted lines) before suddenly moving back to hit the bell.
Qn: Explain why the iron striker would be pulled back
to touch the steel rod when the switch is closed. (2
marks)
Key Concept(s) covered: Electromagnetism, Magnetic
Materials
Student’s Answer: The steel rod attracts (0.5m) the iron
striker.
Teacher’s Answer: When the switch is closed, the steel rod
becomes an electromagnet (1m) and so it will attract
(0.5m) the iron striker, which is a magnetic material/ object
(0.5m).
(Note: Pupil did not explain but merely stated what
happened.)
Qn: Explain why the iron striker would move back to hit
the bell right after being pulled back to touch the rod.
Key Concept(s) covered: Electromagnetism, Electricity,
Open, Closed circuits
Student’s Answer: The steel rod does not stick (0 m) to the
iron striker anymore.
Teacher’s Answer: After the iron striker touches the steel
rod, the circuit becomes open/ circuit is no longer closed
(1m). The electromagnet will lose its magnetism (0.5m),
and no longer attract (0.5m) the iron striker, and so it will
move back to hit the bell.
(Note: Pupil did not use keywords to explain)
Gavin used two identical pieces of paper for an
investigation. He crushed one of the pieces of paper into
a ball. Then he dropped both of the pieces of paper from
the same height as shown below.
Qn: Gavin observed that the crushed piece of paper
reached the ground first. Explain why.
Key Concept(s) covered: Air resistance (frictional force),
surface area
Student’s Answer: The crushed piece of paper reached
the ground first as it is smaller than the flat piece.
Teacher’s Answer: The crushed piece of paper reached
the ground first as it has a smaller surface area (0.5m),
so there is less air resistance (0.5m) acting on the
crushed paper, making it fall faster.
(Note: Though comparative adjective “smaller” is used
correctly, pupil did not use the right keyword to explain)