Question

Which of the following descriptions explains the process of water freezing?

Water molecules speed up until they escape into a different phase.
Water molecules slow down until they begin to bond together.
Water molecules are squeezed together by high pressure until they begin to stick to one another.
As water molecules cool, their shape changes from rounded to irregular, making them more likely to link to one another.

Answer 1

Answer: B. Water molecules slow down until they begin to bond together.

Explanation: When water is cooled, energy is removed from the system, and the molecules begin to slow down. When the molecules have slowed suciently, their collisions are no longer energetic enough to overcome their electrostatic attraction, and they begin to bond together. The other answer choices are inaccurate. Since ice is less dense than water, high pressure compresses the ice and actually causes it to melt. (Compression has no effect on water volume.) Cooling has no effect on the shape of individual water molecules.