Thermal conductivity of Wood and Metal

Ignition temperature for H2 and O2

Relevant Resource questions :

Concepts demonstrated :

• heat transfer by conduction
• ignition temperature

Equipment needed :

• lamp
• bunsen burner and matches
• CCD camera

• light the lamp
• turn on the bunsen burner and point the gas output at the lamp

None.

Physics involved :

The holes in the mesh of the lamp are too small to let the flame of the lamp ignite anything outside of it. Therefore when a bunsen burner is brought near and turned on the gas will not ignite.

However when the lamp is left on long enough the metal mesh of the lamp will heat up. It is then possible to ignite the bunsen.

How to use the Demonstration :

• Ask the students what they think will happen when they point the bunsen burner at the lit lamp.
• Perform the experiment (the bunsen will not light) and ask them to explain why it did nnot light.
• After the lamp has been left on for a long time try to ignite the bunsen again. Ask the students why they think it now ignites.

Things to do or add :

Other Comments :