Conduction, Convection

1
Conduction, Convection Radiation

• (Lovely testy type thing)

2
Conduction

• Which of the following are good conductors
• Aluminium
• Glass
• Copper
• Iron
• Polythene
• Cardboard
• Nickel
• Paper
• Chocolate
• Steel.

3

• Good
• Aluminium
• Copper
• Iron
• Nickel
• Steel

• Bad
• Glass
• Polythene
• Cardboard
• Paper
• Chocolate

4

• What is the special posh sciencey name for a poor
  conductor?
• An insulator
• For the following objects, state whether you
  would want them made out of a good conductor, or
  a good insulator
• The bottom of a saucepan
• The handle of a saucepan
• A duvet/quilt
• An ice cream tub
• An electric hob element

5

• Good conductors
• Bottom of a saucepan
• Electric hob element

• Good Insulators
• Saucepan handle
• Duvet/quilt
• Ice cream tub

6
Convection

• Hot air rises because
• It is less dense than cold air
• Why?
• When something is heated the particles move
  around more and spread out.
• Why does cold gas and liquid fall?
• When it cools the particles move around less,
  move closer together, and therefore become less
  dense.

7
Radiation

• What type of radiation transfers heat?
• Infra-red
• Can infra-red rays travel through space?
• Yes this is how the sun heats the Earth.
  Infra-red rays can pass through a vacuum.
• Do dull or shiny surfaces absorb infra-red
  radiation best?
• Dull
• Do dull or shiny surfaces give off infra-red
  radiation best?
• Dull