Question

A red–hot piece of iron is set on a metal workbench. A student says that it transfers heat to the bench and the air by conduction, and that no other heat transfer takes place. What is wrong with the student's reasoning?

Metal cannot transfer heat by conduction.

Conduction does not work between a solid and a gas.

The metal also gives off heat in the form of radiation.

The iron convects heat to the workbench.

Answer 1

i think it needs radiation

Answer 2

Radiation would be somewhat correct. Everything radiates heat, but usually it isn't substantial unless it is a relatively high temperature (i.e. an incandescent light bulb, heat lamp, fire, the sun etc.)

This would be the second one. I'll explain in a sec.

Answer 3

there is one moe choice!!
Metal cannot transfer heat by conduction

Answer 4

http://openstudy.com/study#/updates/5154fb92e4b0507ceba13e4b

Answer 5

While, a solid and gas CAN technically exchange heat via conduction, it wouldn't be very efficient and would take a very very long time.

The reason is because to be a good conductor you generally need lots and lots of atoms tightly packed together. However, if we look at a conceptual view of a solid and a gas we see this:
As you can see, there aren't a lot of atoms nearby for the gas to readily exchange heat via conduction. Thus, the gas molecules near the solid will be heated, and then due to convection they will rise and cooler gas molecules will take their place.