Effect of frost in rocks :

Things needed :

                 Two paper cups

                 Freezer

                 Plaster of paris

                 Water

                 Scissors

                 Butter knife

Ø  Take a cup of about 3 inches height.

Ø  Prepare plaster of paris in the cup.

Ø  Use the butter knife to cut a narrow one inch deep groove into the plaster of paris before it dries.

Ø  The grooves should not touch the edges of the container.

Ø  Allow it to dry completely.

Ø  Carefully tear the container away to reveal your block. Measure the size of the groove. Fill the groove with water and place the block in the freezer.

Ø  After the water has frozen, remove the block and record your observation. Allow the ice to melt and place it in the freezer again. Repeat this till the block brakes.