Growing Ice -

Purpose: This experiment is used to show that frozen water expands.


1 straw

1 small baby food jar

red or blue food coloring

a permanent marking pen

a piece of clay the size of a marble


  1. Press the ball of clay into the bottom of the center of the jar.
  2. Fil the jar with water.
  3. Add four or five drops of food coloring and stir.
  4. Put the colored straw into the water and push it into the bottom lump of clay. Now the straw can stand on its own.
  5. Slowly pour all of the water out of the jar. Keep the water in the straw.
  6. Use the pen to mark the height of the water in the straw.
  7. Stick the jar in the freezer for about 4 hours or unil you see it's completely frozen. Don't toch while its in the freezer.


What happened to the height of the water?

The frozen water is above the mark you made.


Water molecules are attracted to each other. When they are close to each other, they attract each other and stick or bond together forming hexagonal like structures. As it gets colder these molecules have less flexibility to move and they take up more space. Liquid water molecules on the other hand are free to move around and are more flexible and take up less space than the ice structures.