Lesson Summary Students freeze water in soft plastic vials with caps and in syringes to observe the increase in volume. Students observe a demonstration in which equal volumes of water and ice are weighed on a balance. They predict the behavior of ice in water, place a blue ice cube in a cup of room-temperature water, and observe as the ice melts. Teacher Background When water freezes, it becomes a solid: ice, and ice floats in liquid water. The solid state of every other material sinks in its liquid, because it is denser then the liquid, but not water. Water expands when it turns into a solid. Set-up/Management Tips This lesson has two parts: One session of 15-20 minutes to set up the items to freeze overnight and a second session of 25 to 30 minutes to observe changes on another day. Freezer Space: You will need to be able to store four 1/2 liter containers holding vials and two 1-liter containers holding syringes in the freezer. Be sure to use the soft vial containers for this activity; the smaller hard plastic vials will break if frozen. Freeze 100 ml of water in a plastic cup and keep it as level as possible. Make blue ice cubes. Put 30 drops of blue food coloring in 500 ml of water. You do not need to boil the water as the FOSS manual recommends; the investigation will still work. Literacy Support Books Available Through VAST Mediagraphies (see Literacy Links) Science Stories Ice is Everywhere Ice is History Scientific Vocabulary The following words are key vocabulary words that will be introduced in this lesson and reinforced throughout the unit: No new words introduced in this lesson. Student Instructions - Investigation 2