Question

the diagram shows the motion of a group of water molecules over a heat source. how do the molecules at point a compare to the molecules at point b? they are farther apart. they have increased in size. they have lost energy. they are moving slower.

Explanation:

Step1: Analyze the effect of heat on water molecules

When water is heated (point A), the molecules gain energy.

Step2: Consider molecular behavior with energy gain

As molecules gain energy, they move faster and spread out (inter - molecular distance increases). At point B (cooler region), molecules lose energy, move slower, and are closer. Molecules don't change size (matter conservation), and at A (heated), they gain not lose energy and move faster not slower.

Answer:

They are farther apart.