Growing Crystals

Objectives

Materials

• string
  wide-mouth heat-resistant container (e.g. jar)
  white pipe cleaners
  hot water from a recently boiled kettle (with adult help)
  Epsom salts (available at drugstores)
  pencil

Key Questions

• Where does the salt go when we mix it with water? Can we get the powder back out again? How does your shape look after a few hours? After sitting all night? Where did all those crystals come from? How big a crystal can we grow?

What To Do

1. CAUTION! HOT! Mix Epsom salts into hot water one spoonful at a time. Stir until dissolved (keep adding until there is powder settling on the bottom of the jar that won’t dissolve).
2. Bend a pipe cleaner into a star, heart or any other shape you like. (To make a snowflake, cut the pipe cleaner into thirds. Twist the pieces together in the centre so that you have a six-sided star shape. Wrap string around the outer edges to form a snowflake pattern.)
3. Set the pencil across the mouth of the jar with the pipe cleaner shape suspended and hanging inside.
4. Wait overnight. By morning, the pipe cleaner shape will be covered with shiny crystals. Hang in a window as a sun-catcher or use as a wintertime decoration.

Note: Patience is a virtue! The crystals do require at least a few hours, if not overnight, to take shape.

Extensions

• Try adding food colouring to your solution.

Other Resources

Check out Science World’s preschool resources page for more science fun—from programming under the dome to activities you can do at home!