Penny with water

Penny with water

In this experiment students were asked to predict how many drops of clean water vs soapy would stay on the heads side of a penny before falling off. 

 What did you learn  in this experiment about water?  What improvements could be made the next time this experiment is done?

40 Responses to “Drops of Water on a Penny”
  1. Brooklynn,Montrel says:

    We learned that it does not matter what kind of water we use ( soapy or clean), they are both pretty close in average for numbers and drops of water that stayed on the penny.

  2. robert says:

    We learned that a penny on a heads side can hold more clean water than soapy water. The penny held less drops of soapy water because the molecules got in the way of the water.

  3. lysette,lexi says:

    We learned that soapy water falls off a penny faster than plain water because it’s slippery. We would do it again but more slowly so it can be more accurate.

  4. Alexis, Ricky, and Danays says:

    I learned in this experiment that a penny can hold more clean water then soapy water. Things that I could do differently is watch more carefully and drop the water more slowly. There was 20 drops of clean water and 15 drops of soapy water. I wonder what would happen if we put a penny out in the rain, what do think? I also wonder what would happen if we put soapy water and clean water at the same time? We all enjoyed this experiment and hope to do it again.

  5. science bloggers says:

    In this experiament our group hs learned that clean H2O is more sticky than soapy H2O. We have also learned that soapy H2O runs off of the penny easily than the clean H2O. Next time we will use a different penny for the soapy and claen water. We wonder what will happend if we use a different liquid on the penny. Comment back please !!!!!!!!!!!

  6. KB & AARON says:

    We learned about the attractive properties of surface tension. The soapy water broke but the clean water broke with even more drops on the penny. The clean water had more surface tension than the soapy water. We could have been more careful with our experiment. We could have been faster and stopped wasting time talking and arguing about who got the tools.

  7. B.k. alex says:

    We learned that soapy water had less drops than the clean water. The soapy water had less surface tension.The improvements that we could make to this experiment is that we could stop shaking the table and the water could stop moving. Also we learned to use teamwork and work well with one another. We learned so much while doing this experiment and we encourage you to do the same.

  8. Aleida & Ana says:

    The different kinds of things that we learned from our “Drops of water on a penny” lab is that soapy water has less surface tension. Also, fresh H2O has more surface tension because there were more available drops of clean H2O on the penny than the soapy water. Some improvements that we could do in our next experiment are that we could calculate and graph our results more accurately and also have more knowledge of our goal and hypothesis.
    -Aleida <3
    & Ana:]

  9. outerspace bloggers says:

    In this experiment we learned that clean H2O is more sticky then soapy H2O.Clean H2O also had more drops on the penny surface than the soapy H2O.We have also learned that soapy H2O falls off the penny surface faster then the clean H2O. So remember if you are going to do this experiment be very careful not to breathe above it or move the objects around it. It will make the H2O move and then you will have to restart.

  10. Cayela & Janet says:

    We learned in class about how H20 can be sticky. Clean H20 has less surface tension than soapy H20. Clean H20 can fit more drops on a heads side of a penny than soapy H20. Next time we would try using a different penny because the penny that we used could have been worn down or had smoother edges unlike a new penny. What if we used a different type of liquid or a heated liquid? What do you think? The group next to us could of had a newer penny than we did and they could of had more drops compared to us. Please comment back we are very interested to share your opinions and facts.

  11. Trice and Joss says:

    We learned in this experiment the meaning of surface tenson and that clean H2O is “stickier” than the soapy H2O. We also learned in this experiment that you can get different results everytime you do a trial.The next time we do this experiment we can use a different type of coin, like a quarter or dime or nickel, and instead of using clean H20 VS. soapy H20, we can use hot VS. cold H20, we can also use new coins VS. old coins plus cold and hot H2O at the same time, also we can use clean and dirty H2O at the same time as well. What do you think? We very much enjoyed this experiment. Please come and comment our blog, we would appreciate it very much. Please and thank you!!!

  12. debhanson says:

    Great first blog responses everyone! Keep reflecting and thinking about your experiments. We want to see your work here :-)

    Alexis, Ricky, and Danays – I like your “I wonder…” statements that can lead you to more experiments! That’s good science.

    Aleida & Ana – nice use of the term surface tension. Can you find out why the soap breaks that surface tension?

    B.k. alex – love that you learned to work well together. Sometimes being a good team mate or partner is more important that the actual experiment!

    Trice and Joss – you have lots of new experiments to try (let us know if you test any of those new questions!).

  13. Sarah and Coralys says:

    We learned in this experiment that soapy water is slipery and doesn’t stay on a penny like clean water does. When we used the dropper to see how many clean water droplets would stay on a penny we counted 29 drops of clean water while, soapy water only had about 17 drops of water. The improvments we can make are not going to fast while dropping water on a penny, and different positions for everybody. When everyone is doing the same job it is hard to finish because everyone drops the different waters differently. One person for every different job. If we were to do the experiment again then we would probably get a better observation. If you were to do this experiment take our advice on improving. If not tell us what we should do to improve.

  14. Lixandra and Katie says:

    From our experiment of “Drops Of Water On A Penny” we learned that water has no shape or form and it holds the shape of its container. The penny holds more soapy water than clean water. Surface tension holds the water together until there is too much water and it overflows. One thing we would change about our experiment is that we could have given jobs to each person instead of different people doing the drops of water, because you will end up with different variables or results. Instead we had all the people in our group do different trials.

  15. Amara and Jessica says:

    I learned that water is sticky during our Penny Lab. The attractive property of the surface of a liquid makes the water sticky. Different kinds of water may not be as sticky as clean water. The soapy water fell off the penny and did not stay on as long.
    Improvements we could have made would be having one person be the dropper.

  16. Guinie pig Bloggers says:

    What we learned in this experiment is that the way you position the dropper makes a difference on how many drops you get as a result on the penny. We also learned that our results could be very precise if one person does it. We also enjoyed this experiment because we learned about the diffferent tools you use in the science lab and surface tension. In case you do not know what surface tension is, surface tension is when a liquid is barely over the top and the tension of the water and the surface pull the water down so it does not over flow.

    Guinie pig bloggers <3 =) ;)

  17. The Peepz says:

    We learned that the clean water holds on the penny more than the soapy water. One way we can improve is by testing the experiment over and over again and by testing more we could get new results. We can also improve by working on working together and taking turns and testing the Water On A Penny lab some more. After we get new results we graphed the averages so when we test over and over again we can better averages.

  18. lab ratz says:

    In this experiment we learned that more drops of the clean water fits on a penny then see if the soapy water fits on a penny. It was a very interesting and educating experiment. We have learned a lot and hope to have another experiment like this one we had today.

    Next time we should show more data and show more work and so its easier for other people to understand what we did and what the experiment was about. Also we will use more resources and websites to get more information for the graph. Finally we should recheck the experiment to see if we used the accurate data for this experiment. What do you think?

  19. Mel & Judette says:

    We learned that more drops of clean water would stay on the head side of a penny than soapy water because clean water has more surface tension than soapy water. Some improvements that can be made is that we have to be very careful when doing the experiment because one false move may effect the whole experiment. We really enjoyed the experiment.The experiment was fantastic.

  20. aeroforce1 and hollister says:

    What we learned from the experiment is that when we put about 10 drops of water on the penny it started to make a dome with both the soapy water and clean water. The clean water held more drops of water then the soapy water. An improvement we could have made was we could have tried not to shake the table and we should have tried to not breathe around the penny and water. By accidentally shaking the table and breathing by it, it was almost as if we were coaxing the water to run off the penny.

  21. DCscientists says:

    What we learned about in this experiment was not what we expected.We noticed that the clean water on the penny was high on the top like a bubble, but the soapy water didn’t really stay up because the soapy water had so much chemicals from the soap that it didn’t stick together like the clean water did. But some improvements that we could have done is to try not to shake the table and to have one person do it at a time.

  22. jessica & luz says:

    Well we learned that water can take any shape. It’s not always what meets the eye. We could do better on making sure that the same person uses the dropper for accurate results. Also we could have made sure the tap water was clean and that the air conditioning was off, and made sure nobody was touching the table. We should have made sure the dropper was clean so we wouldn’t have residue from the soapy water. You should try this experiment. It was very exciting. You should blog about your results!

  23. Hollister says:

    Yes, I agree with the outerspace bloggers. You breathe above or around the experiment because when I tried the experiment with my partners we started to get closer when the water was about to run off the penny, but in a result we had to start over because our breath pushed it to one side and caused the water to run off. Another tip I would suggest is that you should keep count carefully because sometimes two drops of water come out of the dropper and you count it as one. That was another mistake me and my partners made.

  24. Mrs. Tew says:

    Well, everyone did a GREAT job on their very first blog! I could not be more proud of a group of students. Keep up the good work and keep thinking like scientists (creative, curious, observant, & skeptical). Stay tuned because I will have a “new” post in a few days for you to comment on. :)

  25. wintrice says:

    I think everyone did a good job. The penny experiment was so much, we got to work in groups and that’s what made it so fun.

  26. anna says:

    Great observations! The specifics listed are great [heads vs. tails], dropper use, etc. *I* learned something new today from you!

  27. Bob Young says:

    Excellent exploration, students! Why do you suppose the “heads” side of the penny might hold more drops than the “tails” side, as recorded by one student. By adding soap to the water, do you change the way it creates surface tension? Would it matter if the penny were brand new as opposed to used? Would tap water behave differently than distilled water?

    Again, excellent work. I applaud you and your teacher(s).

  28. misa says:

    I enjoyed this experiment very much because I learned a lot. My group and I all worked together. We took part in all of the work. We never argued at all. That shows how much we can work together to complete an experiment. <3 ;) :}

  29. Mr. Hanson says:

    When I was in college I learned a particular noteworthy piece of information related to this whole ‘surface tension’ and ‘soap’ thing. Our lungs are comprised of millions of tiny ‘bubbles’ that expand when we breath in. Since these bubbles are covered with liquid (water) this surface tension makes this expansion more difficult. In newborn babies, there is a ‘surfactant’ (like soap) that is secreted into the little bubbles just before they are born, so that newborn babies are able to expand their lungs and breathe. If a baby is born prematurely, BEFORE this surfactant can be secreted into the lungs to allow for this expansion, they quite often are unable to breathe on their own – they need a respirator to breathe for them. This is one of the primary causes of concern for premature babies – those that are born before their ‘due date’.

  30. Michelle Mell says:

    I enjoyed reading about your experiments! Science is such a fun subject. This is a great way to share what you are learning with others! Keep up the good work! I’ll be checking back!

  31. Nivedita says:

    I was looking through this which reminded me about this experiment that I did in 5th grade. It was similar to this one, but we were looking for the number of water droplets that fit on a penny. We were all anticipating it to be five drops at the most. I was very surprised when it reached ten drops. As far as I remember, I think we were able to fit around thirty drops! I’ve never done this experiment before but I agree with your results. Forming a hypothesis for this is pretty easy. How about comparing between oil and soapy water? They’re both slippery so I suppose it’s rather hard to form a hypothesis. What do you think will happen?
    My class is doing a blog about the environment. Please visit:

  32. Mr. Erickson says:

    Great job everyone!!! Your blogs look fantastic. Keep up the good work!!

  33. lab genius says:

    In this experiment we learned about a lot of fun and interesting things such as surface tension. In my opinion, this was a very fun experiment. My science teacher Ms. Tew, did a very good job planning it. Keep up the good work Ms. Tew!

  34. Jarrett says:

    I did this experiment before and it was fun. I got somewhere around twenty drops. My class is blogging about how to save the planet. Check it out:

  35. Mrs. Tew says:

    I checked out your class blog – great articles on the environment. I showed my classes your blog and they were very interested in reading what you and your classmates are writing about. Keep up the good work. We also have a Science Club page on our blog where I give updates about what went on at our monthly meetings. Do you have a Science Club at your school?

  36. guinie pig blogger 2 says:

    Hello Nivedita, I think that forming a hypothesis for comparing oil to soapy water is easy. Here is mine, I think that soapy water will have more drops than oil because oil is thicker and will take up more space than the soapy water because it is thinner.Being slippery though might or might not have an effect on how many drops will fit on the penny. ;) ;> ;}

  37. Houston S. says:

    I am one of Mr. Mcclung’s students and I was just observing your guys blog and that the experiment that you did with the penny and water I thought it was very cool because I did not know that if you put just regular water on a penny that it would fit perfect, and if you put soapy water that it would just slid right off. Maybe I will visit your class blog some other time so come visit ours sometime see you later.. bye.

  38. Tanner says:

    That sounds like a really cool experiment! I should tell my teacher to do it.

  39. Carly says:

    Hi! I’m Carly from Mr.McClung’s class. This is a really interesting project! I never thought about how the soapy water would fall off first because it’s slippery! I would’ve thought it gave it some support! Very awesome project!

  40. Mrs. Tew says:

    Carly & Tanner,
    I’m glad you liked what my class is doing. I also wanted to remind you of the #1 rule of how to stay safe while on the internet. Never give out personal information; using 1st names is OK, but nothing else. Check out my “Things To Remember” page, it is a page of reminders of what to do and what not to do, because sometimes we do forget how big the world really is. Stay safe, have fun, and keep writing.

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