Conductors and insulators
Metals are good conductors of heat energy.
Non-metals and gases are usually poor conductors.
Poor conductors are called insulators.
Heat energy is conducted from the hot end of an object to the cold end.
Applications
The handle of a metal spoon feels colder than the handle of a wooden spoon even though they are side-by-side in the kitchen, and both are at room temperature, which is about 20oC.
Metal is a better conductor than wood, so it conducts heat away from your hand faster than the wooden spoon, making your hand holding the metal feel colder.
Saucepan and frying pan handles are made from plastic or wood which are insulators so that heat does not conduct easily from the hot pan to your hand.
Conduction in liquids
Insert a lump of ice at the bottom of a boiling tube and put a piece of wire gauze on top of it.
Fill the tube with water – the wire gauze will stop the ice floating to the top.
Heat the boiling tube at the top with a Bunsen burner as shown in the diagram.
After a short time, the water at the top of the boiling tube boils but the ice cube does not melt.
This shows that water is a bad conductor of heat energy.
