1. Heat and Temperature
Heat and temperature are
often confused.
They are very different
concepts.

2. Heat and Temperature
There are actually three
concepts that need to be
distinguished:
Heat
Temperature
Thermal energy

3. Heat and Temperature
Heat is the energy
transferred from one
object to another
because of a difference
in temperature.
Heat energy always flows from a hotter object to a colder object.

4. Heat and Temperature
Thermal energy is the
sum total of the energy
of all the molecules in
an object.
Thermal energy all the energy in a single object
Heat energy transferred between two objects

5. Heat and Temperature
Temperature measures
the average energy of
motion of the molecules
in an object.
Fast moving molecules hot object (high temperature)
Slow moving molecules cold object (low temperature)

6. Heat and Temperature
Now test your
understanding with
this three-question
quiz!

7. True or false? An iceberg has more
thermal energy than a cup of coffee.
True
False

8. True or false? An iceberg has more
thermal energy than a cup of coffee.
This is true – you are
correct 
The individual iceberg molecules have much less energy than the
individual coffee molecules. But the total energy of the iceberg is
greater because it has so many more molecules.
Go to question 2

9. True or false? An iceberg has more
thermal energy than a cup of coffee.
Sorry – false is
incorrect 
The individual iceberg molecules have much less energy than the
individual coffee molecules. But the total energy of the iceberg is
greater because it has so many more molecules.
Go to question 2

10. A 1 litre saucepan and a 2 litre
saucepan are both filled with
water, placed on identical stove
elements, and heated. After one
minute:
A. Both pans have received the same amount
of heat and both are at the same temperature.
B. Both pans are at the same temperature
but the 2 litre pan has received more heat.
C. Both pans have received the same
amount of heat but the 1 litre pan is hotter.

11. A 1 litre saucepan and a 2 litre
saucepan, are both filled with
water, placed on identical stove
elements, and heated. After one
minute:
Sorry, option A is incorrect 
Both pans receive the same amount of heat
as they are on identical elements. But the 1
litre pan is hotter because it has half as
many molecules. In fact its temperature
increase is double that of the 2 litre pan.
Go to question 3

12. A 1 litre saucepan and a 2 litre
saucepan are both filled with
water, placed on identical stove
elements, and heated. After one
minute:
Sorry, option B is incorrect 
Both pans receive the same amount of heat
as they are on identical elements. But the 1
litre pan is hotter because it has half as
many molecules. In fact its temperature
increases by double that of the 2 litre pan.
Go to question 3

13. A 1 litre saucepan and a 2 litre
saucepan are both filled with
water, placed on identical stove
elements, and heated. After one
minute:
Yes, option C is correct – well done 
Both pans receive the same amount of heat
as they are on identical elements. But the 1
litre pan is hotter because it has half as
many molecules. In fact its temperature
increases by double that of the 2 litre pan.
Go to question 3

14. 1 kg of water and a 1 kg iron pan are
identically heated. After one minute:
A. Both the water and the iron pan are at the
same temperature.
B. The water is hotter than the pan.
C. The pan is hotter than the water.

15. 1 kg of water and a 1 kg iron pan are
identically heated. After one minute:
Sorry, option A is incorrect 
Because of its molecular structure, iron gets
hotter quicker than water when the same
amount of heat is supplied. That is why pans
quickly become ‘red hot’ on the stove if
there is no liquid to absorb the heat.

16. 1 kg of water and a 1 kg iron pan are
identically heated. After one minute:
Sorry, option B is incorrect 
Because of its molecular structure, iron gets
hotter quicker than water when the same
amount of heat is supplied. That is why pans
quickly become ‘red hot’ on the stove if
there is no liquid to absorb the heat.

17. 1 kg of water and a 1 kg iron pan are
identically heated. After one minute:
Yes, option C is correct – well done 
Because of its molecular structure, iron gets
hotter quicker than water when the same
amount of heat is supplied. That is why pans
quickly become ‘red hot’ on the stove if
there is no liquid to absorb the heat.