Science Assessment

A pot of liquid water and a large block of solid iron are each placed on a stove, which is turned on. How is energy transferred through the iron and the liquid water?

1. Energy will be transferred primarily by convection through the water and by conduction through the iron. The liquid water is free to move from place to place, and its energy moves with it. In the solid iron, the only movement is individual molecules moving back and forth and transferring energy to neighboring molecules when they collide.
2. Energy will be transferred primarily by conduction through both the water and the iron because the molecules that make up both the liquid and the solid are rubbing against each other, and this causes the thermal energy of the molecules to increase. Convection occurs only in large bodies of water, such as oceans, and in the air.
3. Energy will be transferred primarily by convection through both the water and the iron because thermal energy from the hot stove can spread between the molecules of both the liquid and the solid. Conduction occurs only in conductors, such as metal.
4. Energy will be transferred primarily by convection through the water because the liquid water will begin to boil, and the boiling will move the molecules of water and their thermal energy. No energy will be transferred through the iron because the molecules of a solid cannot move and therefore cannot transfer energy.