PL AR RSO P4L22 Heat II WS

Primary 4

Rocket Science OEQ

Name __________________________________________________
Tutor
Topic HEAT II (LESSON 22)

__________________________________________________

HEAT II (LESSON 22)

Primary 4: Rocket Science OEQ
Lesson Outline

• Concept Recall
• Activity 1:Open-ended Questions
• Activity 2: Science in daily life

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Primary 4: Rocket Science OEQ

Concept Recall:

Heat is a form of ______________. Heat
Anything that gives off heat is known as a _____________.

Heat can be generated from ___________, ____________, ______________and
___________________.

____________ is defined as the measure of hotness or coldness of an object. It
is not a form of energy.
Heat is a form of energy that can be transferred from one object of a ________
temperature to another object of a _________ temperature.
Substances can have the _________________ but very ___________________
__________________________.
The units of temperature are _______________________or _______________.
The unit of heat is _____________.

When an object __________________, its ______________________.

Object ______________, temperature ___________.
Object ______________, temperature ___________.

Temperature

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Primary 4: Rocket Science OEQ

How do we measure temperature?

Thermometers are instruments used to measure temperature.

Temperature is the degree of hotness or coldness of an object.

A thermometer is an instrument used to detect or measure changes in
temperature.

Different types of thermometers.

https://www.youtube.com/watch?v=SoYOMi8-
fTY&list=RDCMUC6qf8AGvAGixZXWdxapvCqw&start_radio=1&t=68

The unit of measurement of temperature (Celsius & Kelvin)

Temperature is usually measured in Celsius or Kelvin. The most common
scales are the Celsius scale (°C), the Fahrenheit scale (°F), and the Kelvin

scale (K), the last of which is predominantly used for scientific purposes by

conventions of the International System of Units.

Temperature in Kelvin = Temperature in Celsius + 273

Forehead infrared thermometer Oral digital thermometer

AR Model –
Thermometer

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Primary 4: Rocket Science OEQ

Expansion of matter due to heat gain

Heat causes expansion as it increases the vibration of the particles in a
substance. The vibration forces the particles to move further apart and
the substance becomes bigger and expands

Matter expands when heated.

Expansion

Matter contracts when cooled.

Contraction of matter due to heat loss Contraction

When matter is cooled, it contracts. This is because the particles slow
down and there will be less vibration which results in a closer spacing
between the particles and a contraction of the substance.

Conduction

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Primary 4: Rocket Science OEQ

Activity 1 – Open-ended Questions
1. Vishnu had a metal ball that can pass through a metal ring as shown below.

Metal Ring

Metal Ball Experiment

Vishnu heated up the metal ball using a Bunsen burner and found that the
metal ball could not go through the ring anymore.

(a) Explain why the metal ball could not pass through the ring after being

heated. [1]

_________________________________________________________________

_________________________________________________________________

(b) Suggest one way that will allow the metal ball to go through the [1]
metal ring again.

_________________________________________________________________
_________________________________________________________________

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Primary 4: Rocket Science OEQ

Vishnu then conducted an experiment on a string made of material M. He
measured the length of the same string at different temperatures and recorded
his observation in the table below.

Time Temperature of String M Length of String M
(°C) (cm)
12p.m. 35 110
4p.m.
7p.m. 30 108

25 106

He tied the string made of material M tightly across two poles on a hot
afternoon and left it overnight. The next morning, he found that the string had
snapped as shown in the diagram below.

Day 1 Day 2

(c) Explain why the string snapped. [1]

________________________________________________________

________________________________________________________

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Primary 4: Rocket Science OEQ

2. Peter took a jar of jam out from the refrigerator. His hands felt cold when
he touched the jar.

(a) Explain why his hands felt cold. [1]

_______________________________________________________

_______________________________________________________

He then tried to open it but was unsuccessful. His mother told him to turn
the jar over and dip the cover of the jam into a basin of hot water for one
minute. After that, he was able to remove the cover.

(b) Explain clearly why Peter was able to remove the cover of the jar. [1]
_______________________________________________________
_______________________________________________________

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Primary 4: Rocket Science OEQ

Peter decided to place a similar empty jam jar (uncovered) into a basin of
ice and poured boiling water into it as shown below.

Inner layer Pour boiling water
Outer layer

Ice

Basin

(c) He noticed that the jar started to crack. Explain why. [2]

_______________________________________________________

_______________________________________________________

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Primary 4: Rocket Science OEQ

3. Jane poured 100ml of water into three containers, A, B and C. The containers
are the same size and shape but made of different materials.

She placed each container on a heating plate as shown below.
100ml of water

Heating plate

A BC

The graph below shows the change in temperature of the water over time in
the three containers.

temperature

B
A
C

time

(a) Based on the graph, explain which container, A, B or C, is made of a

material that is the best conductor of heat. [2]

_______________________________________________________

_______________________________________________________

_______________________________________________________

(b) Which container, A, B or C, is the most suitable to be used to hold hot

drinks so that it will keep warm the longest? Explain why. [1]

_______________________________________________________

_______________________________________________________

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Primary 4: Rocket Science OEQ

(c) Jane conducted a second experiment with another 2 containers, X
and Y, made of the same material but with different amounts of water.

In the graph below, fill in the boxes with X and Y to show the change

in temperature of water in both containers. [1]

Heating plate X Y
temperature
150ml of 100ml of
water water

time

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Primary 4: Rocket Science OEQ

4. Max wanted to find out which material A, B or C can conduct heat the best.
He set up an experiment by stacking blocks made from different materials on
top of one another as shown in the diagram below.

Material A Wax
Material B Thumbtack
Material C

Candle

The materials are heated up and the time taken for the thumbtack to drop was
recorded in the table below.

Material Time taken for the thumbtack to drop (min)
A 8
B 2
C 4

(a) Explain why the thumbtacks dropped. [1]

_______________________________________________________

_______________________________________________________

(b) Max’s teacher says that his experiment is not a fair one. Do you agree

with his teacher’s statement? Explain your answer. [1]

_______________________________________________________

_______________________________________________________

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Primary 4: Rocket Science OEQ
Activity 2 – Science in Daily Life: Thermal Expansion - Why are gaps left

between railway tracks?

https://www.youtube.com/watch?v=9JuKqkZVgTU
• What is thermal expansion?
• Where can you find thermal expansion?
• How does this phenomenon apply to thermometers?
• How can trains prevented from derailing?

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