# Heat and Temperature

## Students’ Learning Outcomes

·         Define heat and temperature.
·         Define temperature by using the hotness and coldness of the objects.

### Information for Teachers

·         Heat is the form of energy that is transferred from hot to cold body.
·         Temperature is the degree of hotness or coldness.
·         Temperature is measured by thermometers.

Material / Resources

Candle, match box, taps water, beaker, thermometer, iron rod, wooden block, and textbook

#### Worm up activity

Do the following warm up activities to involve the students:
·         Ask the students the names of some hot and cools objects.
(They may be reply as, “The Sun, a lighted candle, lighted bulb, ice cream etc.)
·         Write down on the board the names of the following things and ask the students to arrange these things in an order that the hottest should be at the left end and the coldest at the right end. (Burning flame, hot tea in the cup, tap water, ice cream).
·         Inform them that everything flame has very high degree of hotness or coldness. This degree of hotness or coldness is called the temperature of that body.

Development

#### Activity 1

·         Place an iron rod on a wooden block.
·         Ask a student to touch both ends of the rod.
·         Put one end of rod in a candle flame for some time.
·         Ask the student to touch its free end.
·         Ask him what does he feel? (It has become hot).
·         Let different students perform this activity.
·         Ask them what results are obtained from this activity?
·         (Accept the answer like, “Heat flows from hot body to cold body” or “Temperature tells the direction of heat flow”)

#### Activity 2

·         Take a beaker filled with some fresh water as shown in figure
·         Ask them to touch in the beaker.
·         Place the iron rod on the wooden block and insert its one end in the beaker.
·         Put the lighted candle under the other end of the rod.
·         After some time ask the students to touch the water again.
·         Inquire about their observations.
(Students’ response “The water is warmer than it was before”)
·         Ask them how was it become warmer?
(Students’ response: The heat energy is transferred from hot end to the cold end of iron rod, so water in the beaker has become warmer)
##### Sum up / Conclusion
·         Heat is a form of energy transferred from hot body to the cold body.
·         Heat changes the temperature of an object.
·         Temperature is the degree of hotness or coldness. It tells direction of flow of heat.
##### Assessment
Ask some question from the students. For example;
·         An electric heater in a room makes it hot. Describe how.
·         An egg is fried in a frying pan over the burner’s flame. Explain how heat is transferred to the egg.
·         In hot summer days, it is difficult to stay in sunlight, what does make it difficult?
·         Tell the students that we will discuss the use of thermometers and the common scales of thermometers in the next session.