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4️⃣ HygieneInfectious diseases aremost often by theHands transmit. Regular and thorough hand washing protects!
🧼 Washing hands
Imagine you had fried chicken for lunch.
“Don’t forget the soap!” calls the mother as Anna goes to the sink with her greasy fingers.
In fact, you can't get rid of the oily film on your skin with just water and no soap, and your hands won't get clean. But why does soap do this immediately?
💡Find out what happens when you put grease and soap together. Instead of soap, use dishwashing liquid in this experiment. Dishwashing liquid acts like strong soap.
Serviceliste
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For the experiment you need the following items:Listenelement 1A 100ml cup with a lid A wooden skewer Oil 2 pipettes Washing up liquid Water Where do we find the most bacteria? Determine 3 different surfaces where you want to collect samples. 3 Petri dishes (either your own or bought) A pen Money Telephone Door handle 3 cotton swabs Distilled water Camera
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PreparationHave all materials ready.
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ImplementationListenelement 31. Fill the cup with water. 2. Use the pipette to add a large drop of oil to the water and observe. Tip: You can add several drops until you have a large drop. Don't add too much force, otherwise you will have lots of small drops. You can use a wooden skewer to combine small drops into one large one. 3. Use the other pipette to add a drop of washing-up liquid to the oil drop.
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WatchListenelement 4a) Observe the drop of oil in the water: where is it and what does it look like? ___________________________________________________________________________________________________________________________________________________________________________________________________________________________ b) Observe carefully for a few minutes what happens when you drop the washing-up liquid into the water. ______________________________________________________________________________________________________________________________________________________________________________________________________________________________
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EvaluationEvaluation a) Soap reacts to fat in a similar way to dishwashing liquid. Discuss with your partner why soap is used to clean greasy hands. ___________________________________________________________________________________________________________________________________________________________________________________________________________________________________ b) You can also draw a picture to go with your ideas, in which you can see the washing of greasy hands through a particularly good special magnifying glass. ______________________________________________________________________________________________________________________________________________________________________________________________________________________________
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How you can continue your researchFind out how to remove the following things from your hands or feet: glue residue, felt-tip pen marks, nail polish, grass stains from a fall, or the remains of a child's tattoo. Write down what you find out: ________________________________________________________________________________________________________________________________________________________________________________________________________________________________
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We want your opinion:Today you have a friend visiting. Your mom calls you to dinner. You go together to wash your hands. Your friend says: "I don't need soap, my hands get clean with water." Think about it: What do you think about that? ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ ______________________________________________________________________________________________________________________________________________________________________________________________________________________________________
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Here is the worksheet to print ⬇️
