Explain why air is not a good conductor of heat.

In a gas molecules have to scatter off molecules to exchange energy in larger distances, so the probability of transfer is much smaller. Air is a bad conductor because, to conduct heat current molecules should absorb heat and transmit it to neighbor by vibrating.

Because It Is not a medal or any type of solid like gas can't conduct heat so air does not get hot it is just waves of heat like "Cold air" is just the area you are in and it could be a cold front

Both models are effective because they show the valence electrons, and these valence electrons indicate the reactivity of an element.