When we put a pan of peas onto the hotplate, heat passes from the hotplate to the pan by [?]. The heat passes through the [?] of the pan by conduction. The pan has a wooden handle to stop us from burning ourselves. This is because wood is a bad conductor of heat; it's a good [?].

When the water heats up, the molecules [?] more, so that the density [?]. The water then rises to the top and heats up the water at the top and the air above. As the water gets cool again, its [?] increases and it falls to the bottom. We can see the peas moving about in the [?] currents.

If we put our hand near a hot pan, we can feel the heat because of [?].