10 minutes maximum! Can you do it in 5?

 

1+2: Heat can travel through substances either through conduction, convection or radiation.

Which of these methods...

1. Works really well in metals?

2. works by hot regions rising, in liquids and gases?

 

3-5. Read the passage below and add the missing words:

Heat radiation can travel through empty space, known as a(n) .
A object will not absorb heat radiation easily.
If you want an object to cool down quickly by losing heat radiation, it should be coloured .
6. This room has an electric heater as well as a cold window. room showing heater and window

The air in the room will...

  • A. move upwards.
  • B. move downwards.
  • C. rotate clockwise.
  • D. rotate anticlockwise.

7. This effect is called...

  • A. a density current.
  • B. a thermal draft.
  • C. a radiation draft.
  • D. a convection current.

8. Why do hot liquids and gases rise upwards?

  • A. Because they are less dense than the surroundings.
  • B. Because they are more dense than the surroundings.
  • C. Because they are lighter than the surroundings.
  • D. Because they are heavier than the surroundings.

Q 9-10. These questions are about hot drink containers:

 drinks containers
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9. Underneath the silver layer in many of these containers is a layer of polystyrene foam. Why is the container often made of a material that traps air?

  • A. To prevent heat loss by conduction
  • B. To prevent heat loss by convection
  • C. To prevent heat loss by radiation
  • D. To make the container lighter.

10. Why does the container have a lid, with only a small gap for the hot liquid?

  • A. To prevent heat loss by conduction
  • B. To prevent heat loss by convection
  • C. To prevent heat loss by radiation
  • D. To make the container lighter.