Friday, June 15, 2007

Science Camp: Day 3

I'm a bit behind in my updating of Science Camp 2007. It is actually done, but I have two updates to make. I also can't find my firewire cable that connects my video camera to my computer. I have some video I want to upload, but unless I find that cable, nothing will be uploaded. Oh, well. I'll worry about that later.

Day 3: We started out day 3 with what we call, Egg Drop Engineering (EDE). The task is to protect an egg from a 5 meter drop. The old classic activity, but one they enjoy. There are scored on whether the egg breaks or not, the number of pieces, the mass of the device, and the accuracy of hitting the target. The twist was that each camper was told to bring 2 items that could be used and they would randomly organized in groups of 3. This meant, they had no idea who their partners were or what they were going to have to work with. They spent about an hour designing and building. The actual drop will occur tomorrow.

They split up into the three groups for the rest of the day. In chemistry, they loaded their DNA fragments from the forensic DNA analysis onto agarose gel. This was very entertaining for me. Visualize 30 5-8th graders trying to pipet 20┬ÁL into a tiny well in an agarose gel. Most of them did pretty good. Some did not. The 100 volts of electricity was applied for an hour. On Thursday they will make a verdict after I stained the gel.

During the remainder of the chemistry time, we did some cyanotyping. Cyanotype is like making a blueprint. A piece of watercolor paper is coated with a solution of potassium ferricyanide (K3Fe(CN)6) and ferric ammonium citrate (Fe(NH4)C6H8O7) to produce the photosensitive compound, iron (III) hexacyanoferrate (III), Fe[Fe(CN)6]. When this paper is exposed to light, the ferric ion (+3) gets reduced to ferrous ion (+2). The ferrous ions then react with the ferricyanide ions of the potassium ferricyanide to produce ferrous ferricyanide (Fe3[Fe(CN)6]2. This blue compound is insoluble in water, but the yellow iron (III) hexacyanoferrate (III) is soluble. In this activity an opaque object in placed on the paper and the paper is taken outside and exposed to sunlight. The solution under the opaque object is then washed away leaving the blue negative.

The demo and snack of the day was liquid nitrogen ice cream. They loved it. I ended up making almost one gallon of ice cream.

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