conduction

Question 1

Which conducts energy better: metals or non-metals?

Answer 1

Metals

Question 2

What is a better conductor than steel?

Answer 2

Copper

Question 3

What conducts better than glass?

Answer 3

Wood

Question 4

Why are metals better conductors than non-metals?

Answer 4

Metals contain free electrons

Question 5

How do these free electrons help in conduction?

Answer 5

They move about at random inside the metal and hold the positive metal ions (charged atoms) in their fixed positions. Then they collide with each other and with the positive ions

Question 6

What happens when a metal rod is heated at one end?

Answer 6

The free electrons at the hot end gain kinetic energy and move faster. These electrons then diffuse and collide with other free electrons and ions in the cooler parts of the metal. As a result, they transfer kinetic energy to these electrons and ions

Question 7

What happens in metals during conduction?

Answer 7

Energy is transferred from the hot end of the rod to the colder end

Question 8

Why is conduction less effective in non-metals than it is in metals?

Answer 8

In a non-metallic solid, all the electrons are held in the atoms. Energy transfer only takes place because the atoms vibrate and shake each other

Question 9

What materials are good insulators?

Answer 9

Wool and fiberglass

Question 10

Why are wool and fiberglass good insulators?

Answer 10

They contain air trapped between the fibres. Trapped air is a good insulator

Question 11

What are materials such as fiberglass used for?

Answer 11

Loft insulation and insulating hot water pipes