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Extension Activity - Crystal Creations

INTRODUCTION

This activity will help you understand how metals form and how they can be changed. You will be able to watch crystals grow and see how they lock together to give shape and strength, then look at what happens to the structure of crystals when they are exposed to various forces.

 
WHAT YOU NEED - Task 1
  • Epsom Salts (available in laundry department of supermarket)
  • Magnifying glass
  • Measuring cup (250ml)
  • Measuring spoon
  • Scissors
  • Black construction paper
  • Lid from a large jar

WHAT TO DO

1) Cut a circle from the black paper that will fit inside the lid. Place the black paper in the lid.
2) Fill the measuring cup with water. Warm water will speed up the process.
3) Add 4 tablespoons (60gm) of Epsom Salts to the water and stir. Pour a very thin layer of the mixture into the lid.
4) Allow the lid to stand undisturbed for one or two days to let the water evaporate.
5) View the crystal formation under a magnifying glass to see how the crystals have locked together.

QUESTIONS

1) What did you notice about the general shape and pattern of the crystals?

_______________________________________________________________________

2) How would this structure give strength, and /or shape?

_______________________________________________________________________

_______________________________________________________________________

WHAT YOU NEED - Task 2 (Can be done at home)

  • Coloured cordial syrup
  • Fork
  • Clear, flexible container
  • Water
  • Freezer

Making icy poles is a good and fun way of seeing how crystals change during the cooling process and when pressure is added, and you can eat the icy pole afterwards!

1) In the container, mix cordial syrup with water to make a strong mixture
2) Put the container in the freezer.
3) View the liquid several times as it is cooling to see what is happening.
4) Squeeze the container at intervals during the freezing process.
5) As the mixture cools, force a fork into the ice crystals. You should be able to change the shape of the substance.

QUESTIONS

1. Compare the strength of the crystalline substance with the original liquid.

____________________________________________________________

2. Do the crystals join up or stay separate? ________________ Does this affect

the end shape? _______________________________________________

3. What happens to the iceblock's shape after pressure is applied to the container?

_____________________________________________________________

4. What happened to the crystals around the edges where you put the fork?

______________________________________________________________

5. In each case, did the new shape remain? ______________________________

6. Could you have done this once the ice had frozen hard? ___________________

7. Use these words to fill in the gaps - shape, crystalline, strength and forces.


Metals like steel have a _____________structure which gives them ___________.


The shape of Steel can be changed by exerting ____________ on it. However, once changed, it keeps its ____________ unless it is re-treated.