CONDUCTION EXPERIMENT: Dropping Pinheads 💎

Conduction is a term used to describe the flow of heat through an object. Objects that are good at conducting heat are called thermal conductors. Metals are thermal conductors, but plastics, fur, wool and gases are usually poor thermal conductors. Poor thermal conductors are called thermal insulators.

When particles at one end of a metal rod are heated, they begin to vibrate more. This causes them to bump into neighbouring particles, making them vibrate more rapidly.

The process of particles bumping into neighbouring particles continues along the metal rod. In this way heat energy is conducted from the hot end of the rod to the cold end, until the entire rod is hot.

AIM: To observe conduction along a metal rod.
EQUIPMENT: A metal rod, retort stand and clamp, Bunsen burner, petroleum jelly, 5-10 drawing pins or small pebbles, a stopwatch. 
METHOD:
1. Set up and light a bunsen burner.
2. Smear a small amount of petroleum jelly on to the head of each drawing pin. 
3. Attach the drawing pins at even intervals along the length of the metal rod.
4. Clamp one end of the metal rod to a retort stand.
5. Position the retort stand to the unclamped end of the metal rod is in the Bunsen burner flame and start the stopwatch.
6. Record the time it takes for each pin to drop in the table below.

EXPLANATION: Using the words particles, vibrating and transfer, explain how to the heat from the Bunsen Burner was conducted along the metal bar. 

When the Bunsen burner flame heated up the end of the metal rod, the particles inside the rod started to vibrate more due to the heat. This resulted in a 'ripple effect' - the vibrating particles bumping into each other so the heat energy is transferred down the road and through the particles, until the entire rod is hot. 

QUESTIONS: 
1. State what the term 'thermal' relates to. 
Thermal relates to the experiment because the retention of the rod's heat was a result of it being thermal conduction (good at flowing heat through an object)

2. Define the term 'thermal insulator'. 
A thermal insulator are objects or material that is poor at flowing and retaining heat through itself. An example of this would be a plastic paperclip - if you held a lighter at one end and held the paperclip at the other, you would not be able to feel the heat of the paperclip, whereas if you do so with a metal paperclip, you would feel the heat and probably get your fingers burned. This is because heat throws through metal easily and is able to transfer from one end from the metal paperclip to another, but it doesn't do the same for thermal insulator materials such as fur, wool, and gases

3. Fish and chips are often wrapped in layers of newspaper to keep them warm.
(A) What's trapped between the layers of newspaper? 
Because paper is a thermal insulator, it is able to trap and retain the heat from the fish and chips.

(B) Using your knowledge of the Particle Theory of Matter, explain why your answer to (A) helps keep the fish and chips warm. 
Because the layers of paper are able to retain heat, the heat from the food does not escape or cool down. The energy conducted from the food is retained by the layers of paper which act as thermal insulators.