Q) Can you explain why ?

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Q) Can you explain why ?
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P1 1.4 Conduction

• Learning objectives
• Describe how energy is transferred in solids by
  heating.
• Explain why some solids are conductors of heat
  and some are insulators.

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Conduction in Metals

• Aim Testing conduction of heat in Metals.
• Describe what I did.
• What happened?
• Can you draw a diagram to explain?
• Can you draw a table of results?
• Q) Which metal should pans
• be made from?

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Conduction in Metals

• Metals are good conductors of heat
• Free electrons surrounds metal atoms
• These gain kinetic energy and go faster
• This makes heat transfer in metals very efficient
• insulators do not have the free electrons.

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ConductionClick conduction in a liquid

• Even in solid matter, like hot pots and cold
  feet, the atoms and molecules are always doing a
  dance, moving up and down and all around. We
  can't see them move, but we can feel their
  energy.
• How?
• As heat!
• Adding heat energy to matter makes its atoms and
  molecules move even faster. As they speed up,
  they bump against their neighbors, and get them
  moving faster too.
• Put a cool pan on a hot stove, and soon the pan
  is hot. If the handle is metal, it will get hot
  too, as the faster-moving molecules in the metal
  pass their energy along.
• That's conduction Matter "conducting" energy
  throughout itself, through molecules bumping into
  each other.
• Q Draw a diagram to explain this or design a
  dance to show how
• the above happens.

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Insulators

• Solids such as___________ do not have free
  electrons, so they are poor conductors of heat,
  or good insulators.
• Most liquids and gases are poor conductors,
  because the particles can move about freely and
  do not pass on energy to one another easily.

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Insulation

• Discuss and plan how the insulating properties of
  a material can be improved.
• OR
• Use different materials to insulate identical
  beakers of hot water.
• Control variables amount of water, starting
  temperature, type of thermometer, same time
  period.

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Animals and insulation

• Q) How are animals are adapted to live in cold
  conditions?
• Insulation to help reduce the transfer of energy
  from their bodies to surroundings.
• Feathers, fat and fur are good insulators.

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Homework challenge.can you do better than
this?
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Questions

• How is energy transferred by conduction?
• Why are liquids and gases poor conductors?
• Explain why materials that are good electrical
  conductors are usually also good at conducting by
  heating.
• Many houses have double-glazed windows. These
  have two sheets of glass with an air gap between
  them. Why does this provide better insulation
  than single glazing?

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• First aiders will often cover someone who has
  been injured outdoors with a very thin blanket
  made of shiny metal foil. Draw a table showing
  the advantages and disadvantages of using foil
  instead of a normal blanket.
• A Look at the pan. Explain why it is made of
  metal and why a chef uses a cloth when picking it
  up. Include the role of free electrons in your
  answer.