Heat and Temperature Heat Gain Prepared by Ms

Heat and Temperature Heat Gain Prepared by: Ms Denise Yeoh

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 (℃)

Introduction

Learning Objectives Today, we are going to learn how to: Explain when objects gain heat.

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.

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.

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.

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.

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.

Key Concepts When an object gains heat, its temperature increases. Note: Only heat can be gained.

Have you been paying attention?

Quiz Time! 1. When an object ____ heat, its temperature _____. 1 2 3 4 gains loses decreases increases

Quiz Time! 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. The temperature of the water increases and the water loses heat. The temperature of the water increases and the water gains heat. 3 4

Global Warming and the Impact of Melting Ice Watch ‘What If All The ICE Melted?