2NT Science: Heat

Answer explanation

TB Pg 121:

11. Heat is a form of energy that flows from a region of higher temperature to a region of lower temperature until both regions reach the same temperature.

TB Pg 123:

17. Heat energy is transferred from the hotter object to the cooler object.

Chan Hao says: "The small fork is hotter than the large fork."

What can be concluded basead on this statement?

• The small fork has gained less heat than the large fork

• The small fork has gained more heat than the large fork.

• The temperature of the small fork is higher than that of the large fork.

• The temperature of the small fork is lower than that of the large fork.

Answer explanation

TB Pg 123:

16. When two objects are at the same temperature, the object with the larger mass will have more heat energy.

• aluminium metal

• oxygen gas

• liquid water

• They expand by the same amount.

Answer explanation

TB Pg 125:

3. Gases generally expand more than solids and liquids when heated, and contract more than slids and liquids when cooled.

https://youtu.be/iVAAnC9eeXk

The graph shows the temperature changes when a beaker of water was heated.

At which point, A, B, C or D, was the heat source removed?

• A

• B

• C

• D

Anaqi wanted to measure the temperature of a beaker of water.

Which set-up shows the correct position of the thermometer?

• A

• B

• C

• D

• A

• B

• C

• D

There are gaps beween metal rails in a railway track as shown.

What happens to the gaps in hot weather?

• The gaps become narrower because the metal rails contract.

• The gaps become narrower because the metal rails expand.

• The gaps become wider because the metal rails contract.

• The gaps become wider because the metal rails expand.

Answer explanation

https://youtu.be/jJeiYaSFCf0

Alice is unable to open the metal cap of a bottle.

What can she do to unscrew the cap?

• Cool the cap only.

• Heat the bottle only.

• Heat the cap only.

• Heat the bottle and the cap.

Exaplain what happens to the liquid in the narrow tube when the thermometer is placed in a beaker of cold water.

Type in: The liquid moves towards the l___ as it c________ when it cools.

Can a thermometer be used to measure the amount of heat? Explain your answer.

Type in: No, as heat depends on the m___ of a substance besides temperature.

A thermometer measures only the t__________ of a substance and not the amount of h___.