How do water molecules near the burner compare to those at the surface in terms of speed and spread?

Water molecules near the burner are more spread out and moving faster due to the heat being applied. When water is heated, the energy from the burner increases the kinetic energy of the molecules. As their kinetic energy increases, the molecules move more rapidly, causing them to overcome some of the intermolecular forces that keep them closely packed together in a liquid state.

This results in a greater distance between the molecules (more spread out) and a higher speed of movement. In contrast, water molecules at the surface are influenced by less heat in comparison to those near the burner, resulting in a slower speed and relatively closer proximity to one another. Thus, the correct choice accurately reflects the effects of heating on the molecular behavior of water.