A student left a sealed jar of water outside her home. Water can be a solid,
liquid, or gas. When she put it outside, the water was a solid. Twelve hours
later, the water had changed phase and was a liquid. What happened to
the water molecules?

a) Before the student left, the molecules were moving in place. After, the molecules were moving around each other.
b) Before the student left, the molecules were moving around each other. After, the
molecules were moving away from each other.
c) Before the student left, the molecules were moving around each other. After, the
molecules were moving in place.
d) Before the student left, the molecules were moving away from each other. After, the
molecules were moving around each other.