Views: 5 Author: Site Editor Publish Time: 2021-04-15 Origin: Site
When children wash their hands, do they find strange lines on their fingers? These special lines are called fingerprints, and everyone has them, but how to clearly observe the shape of the fingerprints in your hand? Today, the Alpha science classroom helps children find fingerprints together through simple chemistry experiment for kids activities. In this process, let the children understand the magic of kid's science experiments. Help the children to become the greatest "Holmes".
Alpha science classroom：how to find fingerprints Materials
A glass or smooth metal surface (where you have permission to test for fingerprints!)
Raw cacao powder if your test surface is light; baby powder if it is dark
White paper if your test surface is light; black paper if it is dark
A small bowl
A fine brush with soft bristles, such as a makeup brush
Alpha science classroom：how to find fingerprints Production program
Step 1: The children choose a finger of a hand and press it firmly on a clean, smooth surface. Remember to place it on the surface. Can you see fingerprints?
Step 2: Children carefully dip the brush in cocoa powder or baby powder. (If your fingerprints are on a dark surface, use baby powder; if on a light surface, use cocoa powder.) Only the tips of the bristles should be covered with talcum powder. Then, tap the brush to remove all excess powder.
Step 3: The children gently swipe the brush across the area where fingerprints are placed. Make sure not to apply too much pressure to avoid wiping off the print. If necessary, add more powder to the brush, but be careful not to add too much. What happens if I apply the powder on the surface? Can you see that fingerprints are developing?
Step 4: After the children are done, gently blow off the excess powder on the surface, and then check the result. Do you have visible fingerprints? How can you see the printed products? Can you recognize the fingerprint pattern?
Step 5: The children use a piece of scotch tape, and then carefully press the tape down onto the surface of the top of the developed fingerprint. Remove the tape and transfer the fingerprint to a piece of paper. (If you use dark cocoa, please use white paper; for baby powder, please use black.) Have you successfully transferred your fingerprints? Does it still look the same on paper compared to glass or metal surfaces?
Finally, the children wash their hands thoroughly with warm water and soap. Then, repeat these steps with the same finger previously selected. Did you get the fingerprint again? How does it look compared to the first one? Can you still see a lot of details?
Finally, apply some hand cream and repeat the fingerprinting step again. How does this fingerprint compare to previous fingerprints? Is it easier to find or harder to find?
After transferring all the fingerprints to a piece of paper, compare the results. Do they all look the same? Which one can you see is the best (least)? Can you explain the result?
Alpha science classroom：how to find fingerprints Observation results
The alpha science classroom tells the children that these invisible potential fingerprints are composed of water, fatty acids, amino acids, and triglycerides, in other words, they are caused by the oils naturally produced by the skin. In order to make them visible, children must find a way to detect one of these substances present in the invisible fingerprint. The simplest method is called dust removal, in which a very fine powder is used, which sticks to the oil on the fingerprint. After the fingerprint is visible, the children lift it from the surface with scotch tape, then transfer it to another surface, and then enter the children's science experiment so for further analysis. Other methods include the use of chemicals that react with amino acids or water in fingerprints, and chemical reactions produce colorful fingerprints that you can easily analyze.
Did the kids collect fingerprints? What are their different patterns? Children can collect fingerprints of their family members and compare them one by one, and they will find that everyone's fingerprints are different. Then, let the Alpha science classroom explain this answer to the children in detail in the future! It is hoped that this chemistry experiment for kids activity could unlock the mystery of fingerprints for children and at the same time show children the fun of kid's science experiment activities. Do Children want more about detective science kits? Please come to Alpha science toys to choose the best detective kits to learn and grow into powerful detectives together!