Solid - Ice
 Forms a rigid structure.
 Molecules have little energy.
 Molecules move VERY slowly.
 Unlike most things, water expands as it
freezes.

This makes it less dense than water.
Therefore, ice floats on water.

Molecular Structure
Why is this a good thing for the
animals that live in water?
Add heat
(____________)
Take out heat
(____________)
Liquid - Water
 Takes shape of its container.
 Molecules move faster, more freely, and
bounce off of each other.
 Water exists as a liquid anywhere from
0 – 100 oC.
Molecular Structure
Add heat
(________________)
Take out heat
(_____________)
Gas – Water Vapor
 Spreads out to fill a space.
 Molecules have a lot of energy.
 Molecules move very fast.
Molecular Structure