Team Kereru and Science

Salt Crystals

Grow Your Own Salt Crystals

What you'll need:

• A jar
• Water
• About half a cup of salt
• A spoon for stirring
• String
• Scissors
• 2 toothpicks

Instructions:

1. Fill the jar with water.
2. Add about half a cup of salt to the water.
3. Mix the solution together with a spoon.
4. Cut a piece of string with scissors and tie each end to a toothpick.
5. Place the string over the top of the jar so that the string dangles into the middle of the solution and the toothpicks hang over the edge.
6. Don’t forget to clean up when you’ve finished.

What next?

Leave the experiment and wait for salt crystals to form along the string. They are an excellent example of cubic crystals and you can do further research with them by examining them under a microscope.

When you look at various crystals under a microscope you can examine the differences between them: Are they perfectly formed? What shape are they? What color? Can you see any microorganisms on the crystals?

Crystals can be found grouped together as lots of small crystals or as huge individual crystals. They vary in size from those at the microscopic level all they way up to crystals that are meters in length!

Try collecting a range of crystals for your project, label the different types and make a rock collection box to keep them in.

Week 6- 20-8-14 Design and Test a Parachute Learn about air resistance while making an awesome parachute! Design one that can fall slowly to the ground before putting it to the test, making modifications as you go. What you'll need: A plastic bag or light material Scissors String A small object to act as the weight, a little action figure would be perfect Instructions: Cut out a large square from your plastic bag or material. Trim the edges so it looks like an octagon (an eight sided shape). Cut a small whole near the edge of each side. Attach 8 pieces of string of the same length to each of the holes. Tie the pieces of string to the object you are using as a weight. Use a chair or find a high spot to drop your parachute and test how well it worked, remember that you want it to drop as slow as possible. What's happening? Hopefully your parachute will descend slowly to the ground, giving your weight a comfortable landing. When you release the parachute the weight pulls down on the strings and opens up a large surface area of material that uses air resistance to slow it down. The larger the surface area the more air resistance and the slower the parachute will drop. Cutting a small hole in the middle of the parachute will allow air to slowly pass through it rather than spilling out over one side, this should help the parachute fall straighter.