Question

Why is air not a good conductor of heat? Select all that apply.

Convection and conduction both happen in air to cause it to heat up.
Conduction requires that molecules are touching one another in order to transfer heat.
Air molecules are spaced close together so that one molecule can cause its neighbor to vibrate easily.
Air molecules are spaced far apart so that one molecule cannot cause its neighbor to vibrate easily.
Conduction can occur even in a vacuum, without the movement of molecules.

Answer 1

Correct choices:
- Conduction requires that molecules are touching one another in order to transfer heat.
- Air molecules are spaced far apart so that one molecule cannot cause its neighbor to vibrate easily.

Brief explanation: Conduction transfers heat by molecular collisions and vibration, so it is inefficient when molecules are far apart (as in gases). In air most heat transfer is by convection and by radiation, not by conduction. The other statements are incorrect or irrelevant: air molecules are not spaced close together, and conduction cannot occur in a vacuum (radiation does).