15. Which of the following choices correctly describes what happens to liquid water if its
molecules slow down enough?
a. A physical change takes place as energy is removed, and it changes to a solid.
b. A physical change takes place as energy is added, and it changes to a gas.
A chemical change takes place as energy is added, and its temperature rises.
d.
A chemical change takes place as energy is removed, and it changes to a solid.