A cook places a pot of water over a flame on a stove. What will happen to the water molecules near the surface of the water?

Question

a. They will become more dense and sink.
b. They will become less dense and sink
c. They will become more dense and rise.

Answer 1

As the pot of water is heated, the water molecules near the surface will absorb heat and begin to move faster. This increase in kinetic energy causes the water molecules to spread apart, making the water less dense. Consequently, as the surface water becomes less dense, it will rise. So, the correct answer is:

None of the options provided correctly describe the behavior of the water molecules at the surface.

However, if the intent was to refer to the behavior of the molecules related to density and movement, then the best understanding is that the water becomes less dense and rises.