Conduction

Question 1

How does conduction take place in non-metals?

Answer 1

As the graphite rod is heated, carbon atoms near the heat source begin to vibrate. The vibrations make the adjacent atoms vibrate, and so on along the rod. This is how heat is transferred in a non-metal.

Question 2

Why are metals good conductors of heat?

Answer 2

Metals contain many free electrons.
The free electrons can move between atoms.
The free electrons carry energy from high-energy atoms to low-energy atoms further away from the heat source.

Question 3

How does conduction take place in non-metals?

Answer 3

As the copper rod is heated, the copper atoms pas on energy in non-metals. The electrons also gain energy but unlike in the atoms, they are free to move around. This. allows them to spread heat energy to atoms further away.

Question 4

Conduction in Liquids

Answer 4

Metals are good conductors of heat almost all non-metals are bad conductors of heat.

Question 5

Are liquids good at conduction heat?

Answer 5

Use some gauze to hold an ice cube at the bottom of a tube of water. Carefully heat the water at the top of the tube until this water is boiling. If the liquid is good at conducting, the ice should quickly melt - it doesn’t. Liquids are poor conductors of heat.

Question 6

Are gases good at conducting heat?

Answer 6

Carefully hold a safety match 1cm away from a Bunsen burner flame (do not put the match in the flame). If a gas is a good conductor, the air between the flame and the match should conduct heat and light the match - it doesn’t. Gases are poor conductors (i.e. good insulators)

Question 7

most conductive to least conductive

Answer 7

Metal(solid), non-metals(solid), liquids, gas, vacuum

Question 8

What happens to particles making up a material when it is heated?

Answer 8

The particles vibrate. The motion of the particles increases as the particles become more energetic.

Question 9

What happens to the particles, if only one end of the material is heated?

Answer 9

The atoms pass on energy. When a substance is heated, its particles gain internal energy and move more vigorously. The particles bump into each other main them vibrate more. This passes internal energy through the substance by conduction from the hot end to the cold end.

Question 10

Will solids, liquids or gases be the best? Why?

Answer 10

Solids will be the best conductors because the particles are closer together than in a gas and are more tightly bound than in a liquid. Heat has conducted through materials by vibration of molecules that are close together.

Question 11

Which will be the poorest conductors (insulators) of heat? Why? Gases or liquids or solids

Answer 11

Gases are the poorest conductors of heat. This is because their particles are widely separated so collisions do not occur frequently to enable efficient energy.

Question 12

What do metals conduct?

Answer 12

electricity

Question 13

What is free to move through metals?

Answer 13

energy, sound, electricity

Question 14

What is an electrical current?

Answer 14

An electrical current is a stream of charged particles such as electrons or ions, moving through an electrical conductor or space.

Question 15

How do these particles help to conduct heat?

Answer 15

?

Question 16

steel uses:

Answer 16

gas pipes
car manufacturing
computers, the average 25% of computers are made from steel

Question 17

wood uses:

Answer 17

used as interiors such as surface materials for walls, ceilings and floors
furniture
insulation

Question 18

aluminium uses:

Answer 18

tin foil
cans
window frames

Question 19

perspex uses

Answer 19

signs
window glazing
car windows

Question 20

What temperature would the steel, wood, aluminium and perspex blocks be?

Answer 20

The blocks would all be the same temperature as the room because the air particles surrounding the objects are the same.

Question 21

What is the best material at transferring heat and is it a conductor or insulator?
steel, wood, aluminium, perspex

Answer 21

We are between 37 and 38 degrees celsius. Steel is better at transferring heat and is a conductor. Conductors are better at transferring heat because insulators trap and try to minimise the transfer of heat.

Question 22

Why don’t the other materials feel as cold as the steel?

steel, wood, aluminium, perspex

Answer 22

The other materials don’t feel as cold because the heat energy is not transferred as fast from our hands.

Question 23

Name poor conductors of heat:

Answer 23

Materials such as wood, glass, paper and wool are poor conductors of heat because they offer very large resistance to the flow of heat current. They are often used as insulators.

Question 24

Name good conductors of heat:

Answer 24

Aluminium, copper, stainless steel and iron are good conductors of heat because they are metals. Cooking utensils are made from good conductors of heat as food can be cooked efficiently in a shorter amount of time.

Question 25

How can non-metals be good conductors of heat?

Give Examples:

Answer 25

Some non-metals can be good conductors of heat for example when a graphite rod is heated the carbon atoms near the heat source begin to vibrate. These vibrations make the adjacent atoms vibrate and so on along the rod. This is how heat is transferred in a non-metal.

Question 26

Conclusion for heat and temperature experiment:

Answer 26

• To boil water we must increase its temperature to 100 degrees celsius. It takes longer to boil a large beaker of water than a small beaker. This is because the larger beaker contains more water and needs to gain more internal energy to reach 100 degrees Celsius.
• In conclusion, the beaker with 100cm3 water heated up faster than the beaker with 200cm3 water showing that the more water there is the slower it heats up. The 100cm3 beaker of water had a larger temperature rise because the same amount of energy was given to a smaller number of particles so each particle is moving faster than those in the other beaker. The 100cm3 beaker of water has a temperature rise of 51 degrees celsius from 20 degrees celsius to 71 degrees celsius. The 200cm3 beaker of water had a temperature rise of 28 degrees celsius from 20 degrees celsius to 48 degrees celsius.