2. Recap
Heat is a form of energy that makes
things hot.
Temperature is a measure of how hot
something is.
Temperature is measured in degree
Celsius (℃)
5. Ice cubes in warm water
What is happening to the ice?
Does ice melt when heat is gained or lost?
What do you think will happen to ice cubes if
we leave them under the sun for 1 hour? Will
the temperature increase or decrease?
The ice will gain heat and melt at O ℃. After
all the ice has melted and become liquid
(water), its temperature will increase.
6. Heat gain
When temperature increases in an object,
there is heat gained in the object.
The heat gained by an object causes an
increase in the temperature of the
object.
7. Let’s practice!
What can we say about the change
in heat in the cold water after some
time?
Claim:The cold water gains heat.
Evidence:The temperature of the
cold water increases after it is left on
the table for some time.
Reason:The temperature of the
water increases when heat is gained
by the water.
8. Why does my ice-cream melt?
What can we say about the change in
heat in the melted ice cream after
some time?
Claim:The melted ice cream gains heat.
Evidence:The temperature of the
melted ice cream increases after some
time.
Reason:The temperature of the melted
ice cream increases when heat is gained
by the melted ice cream.
9. Examples of heat gain
What happens to cool air in an air-
conditioned room when you switch off the
air-condition and open the door for some
time?
Claim:The cool air in the room gains heat.
Evidence:The temperature of air in the room
increases after some time.
Reason:The temperature of the air in the room
increases when heat is gained by the air.
10. Key Concepts
When an object gains heat, its
temperature increases.
Note: Only heat can be gained.
12. QuizTime!
1. When an object ________ heat, its
temperature __________.
1 gains decreases
2 gains increases
3 loses decreases
4 loses increases
13. QuizTime!
2. What happens to cold water after it has been
left on the table for some time?
1 The temperature of the water decreases and the
water loses heat.
2 The temperature of the water decreases and the
water gains heat.
3 The temperature of the water increases and the
water loses heat.
4 The temperature of the water increases and the
water gains heat.