NSES Content Standard B  Physical Science: Properties of objects and materials  Grades K-4, page 127  Materials can exist in different states--solid, liquid, and gas. Some common materials, such as water, can be changed from one state to another by heating or cooling.

 
Benchmark 4B The Physical Setting: The Earth
Grades K-2, page 67
Water can be a liquid or a solid and can go back and forth from one form to the other. If water is turned into ice and then the ice is allowed to melt, the amount of water is the same as it was before freezing.

Benchmark 4D The Physical Setting: Structure of Matter
Grades K-2, page 76
Things can be done to materials to change some of their properties, but not all materials respond the same way to what is done to them.

Benchmark 4D The Physical Setting: Structure of Matter
Grades 3-5, page 77
Heating and cooling cause changes in the properties of materials. Many kinds of changes occur faster under hotter conditions.