Understanding Heat Energy and Its Effects in Daily Life

 
 
 
 
At the end of this unit you should:
1. Be able to show that heat is a form of energy and
that it can be converted into other forms of energy.
2. Be able to identify good and bad conductors of heat
and compare the insulating ability of different
materials.
3. Be able to describe the difference between an
insulator and a conductor.
4. Know how to investigate and explain why matter
expands when heated and contracts when cooled.
5. Be able to explain why water expands on freezing.
 
 
At the end of this unit you should:
6. Be able to measure the temperature of various
solids and liquids at, above and below room
temperature.
7. Understand the difference between heat and
temperature.
8. Know how to carry out experiments that involve
changes of state from:
• solid to liquid and liquid to solid
• liquid to gas and gas to liquid.
9. Be able to plot a cooling curve/heating curve and
use latent heat to explain the shape of the curve.
 
bimetallic strip
conduction
conductor
convection
convection current
energy
expansion
heat
insulator
joules
latent heat
radiation
specific heat capacity
temperature
thermometer
vacuum
LIGHTBULB QUESTION
 
Fire, warm, heating things
up, cooking, temperature or
objects being hot.
 
 
Heat
:
A form of energy. Unit: the joule (J).
 
(a) Looking at 
Fig. 11.02.01
, can you list the objects where
you think heat is being given out.
 
Radiator, TV, fireplace, wall lamps.
(b) Suggest a reason as to why you feel the heat from a fire
in a room.
 
 
Heat has energy and it is the energy we can feel.
 
 
Conduction:
The transfer of heat energy through a solid by the vibration
of particles.
 
(a) Define heat.
 
Heat is a form of energy.
(b) What is the unit of heat?
 
The unit of heat energy is the joule (J).
(c) Complete the sentence, ‘Heat is a form of_______’.
 
energy
(d) Why, when we put a poker into a fire, does the poker burn our
hands?
 
 
It is made of a metal, which is a poor conductor or heat.
Investigation 11.02.01: Good and bad conductors
Equipment: 
Wax, some metal rods (copper, aluminium, brass,
nickel and steel), some identical nails, Bunsen burner, tripod,
drawing pin and wire gauze.
 
Investigation 11.02.01: Good and bad conductors
Instructions:
1. Align all rods so that at one end, the rods are touching, with the
other ends spread away from each other.
2. Place some Vaseline or wax at the spread end of the rod and
attach a drawing pin to each, facing down.
3. Now place the Bunsen burner under the end of the rods that are
touching and heat up the rods.
4. Take note of which drawing pins drop first.
 
 
 
 
 
1. Compare which metal was the best conductor and which was
the worst.
This depends on the metals you use. If copper is used, it will be
the first to see the nail/drawing pin fall off.
 
2. How did you ensure this was a fair test?
Same length and thickness was kept for all the metals. All were
heated evenly and the same amount of wax was used for each
nail/drawing pin.
 
3. What other substances could you have used instead of wax?
Parafilm, Vaseline or any other suitable substitute.
 
 
Conductor
:
Allows heat energy to transfer through it easily.
 
 
 
 
Insulator
:
Does not allow heat energy to transfer through it easily.
 
 
Convection
:
The transfer of heat through a liquid or gas.
LIGHTBULB QUESTION
 
Warm air rises. Birds can use
this effect to glide/hover in
the air, conserving their
energy while looking for
prey. This use of convection
currents is most commonly
seen in eagles.
 
(a) Put your hand over a warm radiator. What do you feel?
That heat rises from the radiator.
 
(b) Where does the steam come from when a kettle of water
boils?
The steam comes from the boiling of water inside the kettle.
Equipment:
Spatula-tip of potassium permanganate crystals, water, beaker,
tripod stand, wire gauze, Bunsen burner/hot plate.
Demonstration 11.02.01 – Showing a convection current
DEMONSTRATION
 
Instructions:
1. Fill a beaker with water.
2. Gently place some potassium permanganate crystals into the
bottom left of the beaker.
3. Allow some time for the crystals to settle.
4. Heat the bottom of the beaker where you have placed the
crystals.
5. Watch as the convection currents form.
DEMONSTRATION
 
Vacuum:
A region of space where all atoms have been removed.
 
 
 
Radiation:
The transfer of heat energy from a hot object without particles.
LIGHTBULB QUESTION
 
White-coloured clothing reflects the
heat, dark-coloured clothing absorbs
the heat. So by that logic one should
wear light-coloured clothing in the
summer and dark colours in the winter.
However, people who live in desert
areas generally wear black, loose-
fitting clothing. This is because the
black absorbs the light, preventing it
from reaching the skin. As the fabric
heats up, the hot air rises, with cold air
rising up from the feet, effectively
creating a fan inside the robe. So the
answer isn’t as black and white as it
seems!
 
(a)
How many methods of heat transfer are there? Name these
methods.
Three: Conduction, convection and radiation.
 
(b) ‘All metals are good conductors of heat.’ Give your own
opinion on this statement and back it up with evidence.
All metals can conduct heat. However, some of them are not
good conductors. For example, the metal used in a fire poker is
an example of an insulator; if it were a good conductor of heat,
it would burn the hand of the user.
 
(c) ‘If you want to heat up your house, your radiators should be
made of insulating material.’ State your opinion on this theory
and give evidence for your opinion.
If radiators were made of insulating material, they would not
allow the heat to escape. This is why radiators are made of
aluminium. The standard hot-water radiator works via
convection.
Investigation 11.02.02: The heating effect on a metal
Equipment: 
Ball and ring apparatus, Bunsen burner.
 
Investigation 11.02.02: The heating effect on a metal
Instructions:
1. Using the ball and ring apparatus, try to place the ball through
the ring and note what happens.
2. Heat the ball using the Bunsen burner.
3. Try to place the ball through the ring and note what happens.
 
 
 
 
 
1. What did you observe in your investigation?
When cool, the ball would fit through the ring. When the ball
was heated it no longer fitted through the ring.
 
2. What would you need to do if you wanted to repeat this
investigation multiple times?
The ball would need to be cooled back to room temperature.
This can be achieved by putting it in water.
 
3. What safety precautions did you take when conducting this
investigation?
Heat-resistant gloves were worn when heating and handling
the ball and ring apparatus. Full PPE was also worn.
 
Explain how a bimetallic strip works and name the two metals
used.
Two metals, usually iron and copper, are welded together.
Copper will conduct heat energy faster than iron and therefore
expand more. This expansion causes the strip to bend a certain
way, depending on where the copper is placed.
 
 
Temperature
:
The measure of how hot or cold an object is.
LIGHTBULB QUESTION
 
Getting burnt by steam at 100˚C is
worse than getting burnt by water at
100˚C. This is because the steam has
more energy in it due to the latent
heat. Therefore, the gas (steam) must
first change its state from gas to liquid
at 100˚C. Then the liquid needs to cool
down. Water at 100˚C can start to cool
down straight away as there is no
change in state.
 
Specific Heat Capacity:
The amount of energy needed to change the temperature of a 1
kg substance by 1
o
C.
 
Latent Heat:
The heat energy required to change a substance from one state
to another without a change in temperature.
Investigation 11.02.03: The effects of heat on ice
Equipment: 
Bunsen burner/hot plate, ice cubes, beaker, tripod,
wire gauze and thermometer.
 
Investigation 11.02.03: The effects of heat on ice
Instructions:
1. Set up the equipment as shown.
2. Take the ice out of the freezer and dry it by patting it lightly with
laboratory paper, and then crush it slightly.
3. Place the ice into a beaker along with a thermometer.
4. Allow the ice to melt and take measurements of the temperature
every 1–2 minutes.
5. Once the ice has melted, allow additional time for the
temperature to settle above 0 degrees.
6. Now heat the beaker up using a Bunsen burner. Take note of the
temperature every minute.
7. Continue to take measurements until most of the water has
been evaporated.
 
 
 
 
 
1. How did you ensure this was a fair test?
By ensuring the ice was dry, the water was stirred throughout
the experiment and measurements were taken at regular
intervals.
 
2. Is your graph similar to 
Fig. 11.02.11
? If so, tell the story of
this graph. If not, explain the story of your graph and suggest
possible reasons why your graph is different.
Possible reasons for difference in graphs: water was not stirred
between measurements; not enough time given between
changes in state.
 
 
3. Does your graph show latent heat? Justify your answer.
Graph should show a horizontal line at 0 and 100 degrees as
this is the change in state with no change in temperature.
Example:
Copy and Complete
In this unit I learned that 
heat
 is a form of 
energy
. There are 
three
methods for heat transfer. Conduction is the transfer
of heat through a 
solid
 via the 
vibration
 of 
molecules
. 
Convection
is transfer of heat through a liquid via the 
movement
of particles through a 
convection
 
current. Radiation is the transfer
of heat through a 
vacuum 
via 
electromagnetic 
radiation. If an
object allows heat to pass through it easily it is called a 
conductor
.
If it does not allow heat to pass through it easily it is called an
insulator
. When heated, 
solids
, 
liquids
 and 
gases
 all expand.
Similarly when cooled, 
solids
, 
liquid
 
and 
gases
 all contract.
Temperature is the measure of how 
hot
 or 
cold
 
a body is. I must
remember that 
temperature
 is not the same as 
heat
.
 
 
 
 
1. Explain temperature.
The degree of heat present in a substance or object.
 
2. Distinguish between temperature and heat.
Heat is a form of energy. Temperature is the measure of how hot
or cold an object/substance is.
 
3. Define latent heat.
The heat energy required to change a substance from one state
to another without a change in temperature.
 
4. What are the four states of matter?
Solid, liquid, gas and plasma.
 
 
 
5. Using diagrams to justify your explanation, describe how much
energy particles have in the three states of matter.
 
 
 
 
 
6. Describe how to calibrate an alcohol thermometer.
 
To calibrate a thermometer (mark it with a standard scale to
read it), we only need two measurements: 100˚C and 0˚C, both
of which are easy to determine. When a thermometer is made, it
is placed in boiling water. This is because water boils at 100˚C. A
mark is made when the liquid reaches its reading for this
temperature. Next the water is placed in ice water because ice
water is 0˚C. This point is also marked. Then, marks are made at
intervals of 1˚C.
 
 
 
 
 
7. Latent heat changes the state of the substance without
changing the temperature. Using your knowledge of bonding, can
you suggest the reason why there is no increase in temperature?
Take ice for example. Ice is solid water. This means the particles
are all compact and tight together. As we pump energy into the
ice, it begins to melt. This is due to the particles gaining energy
and their vibrations intensifying. Once we hit the latent heat
phase of this process, all the energy being pumped into the
molecules is actually being used to break these bonds, i.e. free
the molecules from the solid, so no energy is being given to
increase its temperature. Once all the molecules are free, they
become a liquid and the heat energy is now used to increase the
temperature of the molecules.
8. Peter is working on repairs to an old house. He has left a bottle
of water, some metal nails and a piece of timber inside the boot
of his car. After the car has been out in the sun for three hours,
the temperature inside the car reaches about 40
o
C. What
happens to the objects in the car? Copy and complete Table
11.02.01 by answering ‘Yes’ or ‘No’ for each statement, and give
your reasons.
8. Peter is working on repairs to an old house. He has left a bottle of
water, some metal nails and a piece of timber inside the boot of his
car. After the car has been out in the sun for three hours, the
temperature inside the car reaches about 40
o
C. What happens to
the objects in the car? Copy and complete 
Table 11.02.01 
by
answering ‘Yes’ or ‘No’ for each statement, and give your reasons.
9. 
Table 11.02.02 
shows the data collected for the cooling curve of
chocolate.
(i) Draw the cooling curve for the data contained in 
Table
11.02.02
.
(i) Draw the cooling curve for the data contained in 
Table 11.02.02
.
 
 
 
 
(ii) Which state of matter describes the chocolate when it is at 30˚C?
Liquid.
 
 
 
 
(iii) Which state of matter describes the chocolate when it is at 10˚C?
Solid.
 
 
 
 
(iv) In terms of heat loss or heat gain, describe and explain what
happens to the chocolate between position A and position B in 
Fig.
11.02.12
. (
2014 JC HL
)
The distance between these points represent latent heat, so no
change in temperature occurs but a change in state occurs.
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Explore the world of heat energy through this unit to learn about its conversion, conduction, insulation, expansion properties, and more. Discover how heat affects various materials, why water expands when frozen, and the difference between heat and temperature. Engage in experiments to understand state changes and utilize latent heat in cooling and heating curves.


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  1. At the end of this unit you should: 1. Be able to show that heat is a form of energy and that it can be converted into other forms of energy. 2. Be able to identify good and bad conductors of heat and compare the insulating ability of different materials. 3. Be able to describe the difference between an insulator and a conductor. 4. Know how to investigate and explain why matter expands when heated and contracts when cooled. 5. Be able to explain why water expands on freezing.

  2. At the end of this unit you should: 6. Be able to measure the temperature of various solids and liquids at, above and below room temperature. 7. Understand the difference between heat and temperature. 8. Know how to carry out experiments that involve changes of state from: solid to liquid and liquid to solid liquid to gas and gas to liquid. 9. Be able to plot a cooling curve/heating curve and use latent heat to explain the shape of the curve.

  3. bimetallic strip insulator conduction joules conductor latent heat convection radiation convection current specific heat capacity energy temperature expansion thermometer heat vacuum

  4. LIGHTBULB QUESTION Fire, warm, heating things up, cooking, temperature or objects being hot.

  5. Heat: A form of energy. Unit: the joule (J).

  6. (a) Looking at Fig. 11.02.01, can you list the objects where you think heat is being given out. Radiator, TV, fireplace, wall lamps.

  7. (b) Suggest a reason as to why you feel the heat from a fire in a room. Heat has energy and it is the energy we can feel.

  8. Conduction: The transfer of heat energy through a solid by the vibration of particles.

  9. (a) Define heat. Heat is a form of energy. (b) What is the unit of heat? The unit of heat energy is the joule (J). (c) Complete the sentence, Heat is a form of_______ . energy

  10. (d) Why, when we put a poker into a fire, does the poker burn our hands? It is made of a metal, which is a poor conductor or heat.

  11. Investigation 11.02.01: Good and bad conductors Equipment: Wax, some metal rods (copper, aluminium, brass, nickel and steel), some identical nails, Bunsen burner, tripod, drawing pin and wire gauze.

  12. Investigation 11.02.01: Good and bad conductors Instructions: 1. Align all rods so that at one end, the rods are touching, with the other ends spread away from each other. 2. Place some Vaseline or wax at the spread end of the rod and attach a drawing pin to each, facing down. 3. Now place the Bunsen burner under the end of the rods that are touching and heat up the rods. 4. Take note of which drawing pins drop first.

  13. 1. Compare which metal was the best conductor and which was the worst. This depends on the metals you use. If copper is used, it will be the first to see the nail/drawing pin fall off. 2. How did you ensure this was a fair test? Same length and thickness was kept for all the metals. All were heated evenly and the same amount of wax was used for each nail/drawing pin. 3. What other substances could you have used instead of wax? Parafilm, Vaseline or any other suitable substitute.

  14. Conductor: Allows heat energy to transfer through it easily.

  15. Insulator: Does not allow heat energy to transfer through it easily.

  16. Convection: The transfer of heat through a liquid or gas.

  17. LIGHTBULB QUESTION Warm air rises. Birds can use this effect to glide/hover in the air, conserving their energy while looking for prey. This use of convection currents is most commonly seen in eagles.

  18. (a) Put your hand over a warm radiator. What do you feel? That heat rises from the radiator. (b) Where does the steam come from when a kettle of water boils? The steam comes from the boiling of water inside the kettle.

  19. DEMONSTRATION Demonstration 11.02.01 Showing a convection current Equipment: Spatula-tip of potassium permanganate crystals, water, beaker, tripod stand, wire gauze, Bunsen burner/hot plate.

  20. DEMONSTRATION Instructions: 1. Fill a beaker with water. 2. Gently place some potassium permanganate crystals into the bottom left of the beaker. 3. Allow some time for the crystals to settle. 4. Heat the bottom of the beaker where you have placed the crystals. 5. Watch as the convection currents form.

  21. Vacuum: A region of space where all atoms have been removed. Radiation: The transfer of heat energy from a hot object without particles.

  22. LIGHTBULB QUESTION White-coloured clothing reflects the heat, dark-coloured clothing absorbs the heat. So by that logic one should wear light-coloured clothing in the summer and dark colours in the winter. However, people who live in desert areas generally wear black, loose- fitting clothing. This is because the black absorbs the light, preventing it from reaching the skin. As the fabric heats up, the hot air rises, with cold air rising up from the feet, effectively creating a fan inside the robe. So the answer isn t as black and white as it seems!

  23. (a) How many methods of heat transfer are there? Name these methods. Three: Conduction, convection and radiation. (b) All metals are good conductors of heat. Give your own opinion on this statement and back it up with evidence. All metals can conduct heat. However, some of them are not good conductors. For example, the metal used in a fire poker is an example of an insulator; if it were a good conductor of heat, it would burn the hand of the user.

  24. (c) If you want to heat up your house, your radiators should be made of insulating material. State your opinion on this theory and give evidence for your opinion. If radiators were made of insulating material, they would not allow the heat to escape. This is why radiators are made of aluminium. The standard hot-water radiator works via convection.

  25. Investigation 11.02.02: The heating effect on a metal Equipment: Ball and ring apparatus, Bunsen burner.

  26. Investigation 11.02.02: The heating effect on a metal Instructions: 1. Using the ball and ring apparatus, try to place the ball through the ring and note what happens. 2. Heat the ball using the Bunsen burner. 3. Try to place the ball through the ring and note what happens.

  27. 1. What did you observe in your investigation? When cool, the ball would fit through the ring. When the ball was heated it no longer fitted through the ring. 2. What would you need to do if you wanted to repeat this investigation multiple times? The ball would need to be cooled back to room temperature. This can be achieved by putting it in water. 3. What safety precautions did you take when conducting this investigation? Heat-resistant gloves were worn when heating and handling the ball and ring apparatus. Full PPE was also worn.

  28. Explain how a bimetallic strip works and name the two metals used. Two metals, usually iron and copper, are welded together. Copper will conduct heat energy faster than iron and therefore expand more. This expansion causes the strip to bend a certain way, depending on where the copper is placed.

  29. Temperature: The measure of how hot or cold an object is.

  30. LIGHTBULB QUESTION Getting burnt by steam at 100 C is worse than getting burnt by water at 100 C. This is because the steam has more energy in it due to the latent heat. Therefore, the gas (steam) must first change its state from gas to liquid at 100 C. Then the liquid needs to cool down. Water at 100 C can start to cool down straight away as there is no change in state.

  31. Specific Heat Capacity: The amount of energy needed to change the temperature of a 1 kg substance by 1oC. Latent Heat: The heat energy required to change a substance from one state to another without a change in temperature.

  32. Investigation 11.02.03: The effects of heat on ice Equipment: Bunsen burner/hot plate, ice cubes, beaker, tripod, wire gauze and thermometer.

  33. Investigation 11.02.03: The effects of heat on ice Instructions: 1. Set up the equipment as shown. 2. Take the ice out of the freezer and dry it by patting it lightly with laboratory paper, and then crush it slightly. 3. Place the ice into a beaker along with a thermometer. 4. Allow the ice to melt and take measurements of the temperature every 1 2 minutes. 5. Once the ice has melted, allow additional time for the temperature to settle above 0 degrees. 6. Now heat the beaker up using a Bunsen burner. Take note of the temperature every minute. 7. Continue to take measurements until most of the water has been evaporated.

  34. 1. How did you ensure this was a fair test? By ensuring the ice was dry, the water was stirred throughout the experiment and measurements were taken at regular intervals. 2. Is your graph similar to Fig. 11.02.11? If so, tell the story of this graph. If not, explain the story of your graph and suggest possible reasons why your graph is different. Possible reasons for difference in graphs: water was not stirred between measurements; not enough time given between changes in state.

  35. 3. Does your graph show latent heat? Justify your answer. Graph should show a horizontal line at 0 and 100 degrees as this is the change in state with no change in temperature. Example:

  36. Copy and Complete In this unit I learned that heat is a form of energy. There are three methods for heat transfer. Conduction is the transfer of heat through a solid via the vibration of molecules. Convection is transfer of heat through a liquid via the movement of particles through a convection current. Radiation is the transfer of heat through a vacuum via electromagnetic radiation. If an object allows heat to pass through it easily it is called a conductor. If it does not allow heat to pass through it easily it is called an insulator. When heated, solids, liquids and gases all expand. Similarly when cooled, solids, liquid and gases all contract. Temperature is the measure of how hot or cold a body is. I must remember that temperature is not the same as heat.

  37. 1. Explain temperature. The degree of heat present in a substance or object. 2. Distinguish between temperature and heat. Heat is a form of energy. Temperature is the measure of how hot or cold an object/substance is. 3. Define latent heat. The heat energy required to change a substance from one state to another without a change in temperature. 4. What are the four states of matter? Solid, liquid, gas and plasma.

  38. 5. Using diagrams to justify your explanation, describe how much energy particles have in the three states of matter.

  39. 6. Describe how to calibrate an alcohol thermometer. To calibrate a thermometer (mark it with a standard scale to read it), we only need two measurements: 100 C and 0 C, both of which are easy to determine. When a thermometer is made, it is placed in boiling water. This is because water boils at 100 C. A mark is made when the liquid reaches its reading for this temperature. Next the water is placed in ice water because ice water is 0 C. This point is also marked. Then, marks are made at intervals of 1 C.

  40. 7. Latent heat changes the state of the substance without changing the temperature. Using your knowledge of bonding, can you suggest the reason why there is no increase in temperature? Take ice for example. Ice is solid water. This means the particles are all compact and tight together. As we pump energy into the ice, it begins to melt. This is due to the particles gaining energy and their vibrations intensifying. Once we hit the latent heat phase of this process, all the energy being pumped into the molecules is actually being used to break these bonds, i.e. free the molecules from the solid, so no energy is being given to increase its temperature. Once all the molecules are free, they become a liquid and the heat energy is now used to increase the temperature of the molecules.

  41. 8. Peter is working on repairs to an old house. He has left a bottle of water, some metal nails and a piece of timber inside the boot of his car. After the car has been out in the sun for three hours, the temperature inside the car reaches about 40oC. What happens to the objects in the car? Copy and complete Table 11.02.01 by answering Yes or No for each statement, and give your reasons.

  42. 8. Peter is working on repairs to an old house. He has left a bottle of water, some metal nails and a piece of timber inside the boot of his car. After the car has been out in the sun for three hours, the temperature inside the car reaches about 40oC. What happens to the objects in the car? Copy and complete Table 11.02.01 by answering Yes or No for each statement, and give your reasons. Does this happen to the object(s)? Yes or No? Reason The car is at 40oC. They all have the same temperature. After some time the water begins to boil. After some time the metal nails begin to glow red. Yes Water boils at 100oC. No No The temperature is not high enough for this to happen.

  43. 9. Table 11.02.02 shows the data collected for the cooling curve of chocolate. (i) Draw the cooling curve for the data contained in Table 11.02.02.

  44. (i) Draw the cooling curve for the data contained in Table 11.02.02.

  45. (ii) Which state of matter describes the chocolate when it is at 30C? Liquid.

  46. (iii) Which state of matter describes the chocolate when it is at 10C? Solid.

  47. (iv) In terms of heat loss or heat gain, describe and explain what happens to the chocolate between position A and position B in Fig. 11.02.12. (2014 JC HL) The distance between these points represent latent heat, so no change in temperature occurs but a change in state occurs.

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