Friday, August 10, 2012

Elementary Science Fair Projects - Growing Crystals [sciencetechnology-center.blogspot.com]

Elementary Science Fair Projects - Growing Crystals [sciencetechnology-center.blogspot.com]

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In this elementary science fair project we are going to look at crystals and we are going to try and grow crystals. In nature we find crystals in all shapes and sizes. We get ones that are considered valuable, like diamonds, and others that are not considered so valuable. All crystals have their own quality and are beautiful. Crystals are easy to grow and are therefore a very suitable elementary science fair project.

The definition of a crystal according to the Oxford Dictionary:

A piece of a homogeneous solid substance having a natural geometrically regular form with symmetrically arranged plane faces. Chemistry: any solid consisting of a symmetrical, ordered, three-dimensional aggregation of atoms or molecules. A clear transparent mineral, especially quartz.

For our elementary science fair project we are going to grow crystals in a gelatin solution. Because heat is going to be used, this science experiment should be done under adult supervision.

What you will need for this experiment:

A 1-pint glass jar A ¼ cup of table sugar A ½ Cup of distilled water 0.25 ounce of unflavored gelatin A small saucepan Spoon The method for this elementary science fair project:First you have to pour the water into your saucepan. Now you sprinkle the gelatin over the water and allow it to soak for a few minutes. Place the saucepan on the stove and heat the water while you are stirring to dissolve the gelatin completely in the water. Continue stirring while you add the sugar. Continue until the sugar is completely dissolved in the water. After the solution (what is a solution?) has cooled down for about 5 minutes you have to pour it carefully into your jar. Now you have to leave the jar undisturbed for at least two weeks. Make daily observations and write them down carefully. It might even be a good idea to take photos of your elementary science fair project every day to use in your display. Remember a good display is almost as important as the experiment! Take note that more than one thing happens at a time with this experiment. What are the two things? Why is it happening?

If you did this elementary science fair project right, the gelatin in the water will cause the water to set. (Think jello!) The other thing that happens is that after a few days clear crystals form inside the gel and it appears to be suspended throughout the gel. Remember to take photos every day to show how the crystals grow bigger and bigger every day. You can also draw charts to show how the crystals are formed throughout the gel.

Now you also have to be able to explain why it happens:

As you heat the water, more of your solute (that what is dissolved in the water) will dissolve in the water (called your solvent) as would have when the water is cold. Now when the water starts to cool there is more sugar dissolved in the water than would normally have been dissolved in it. Now we get what is called a supersaturated solution.

Now, as the water evaporates your solution becomes even more supersaturated and it becomes unstable, now any disturbance wi ll cause the microscopic molecules of the solute to stick together and form crystals. At first the crystals are too small to be seen but, as they grow they become bigger and visible as they form clumps throughout the gel. The reason for the gel in your elementary science fair project is to keep the crystals suspended and thus ensuring that many crystals form.

For an even better elementary science fair project you can do more than one experiment. Repeat the above but change some of the conditions. See what happens of the solution cools down slower by maybe placing your jar in a big thermos flask. You can also use a bottle with a narrow mouth instead of the jar and see if the slower evaporation of the water makes a difference. You can even make a solution with different kinds of sugar such as sucrose glucose and fructose and see what happens then. The possibilities are endless and this elementary science fair project can be as simple or as involved as you would like.

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